A while back, I was at physical therapy, and the topic of tennis came up. Someone said something about yellow tennis balls, and I was like… “What? They’re green.” And then someone else chimed in, “No, they’re yellow!” And then someone across the room hollered, “No, they’re obviously green.”

There was basically a physical therapy uproar. And when I started asking other people how they saw them — yellow or green — they told me they couldn’t even believe there was a debate. So I called up Bevil Conway. He’s a neuroscientist who heads up a lab at the National Eye Institute. He’s working on a book called Color Coded, which is due out next year. And he’s also a working artist — which is actually how he got into studying color in the first place. 

Conway told me there’s a pretty good reason for why so many people disagree about tennis balls. He said it’s simple: “There’s no such thing as a color.”

In the latest episode of Unexplainable, I talked with Conway about what color even is, the viral dress fight (black and blue or white and gold?), and why we get so upset when people don’t see color the same way we do. Below is an excerpt of our conversation, edited for length and clarity. Listen to the episode anywhere you get your podcasts or you can watch on Netflix.

So you are an artist. You are also a neuroscientist. You study color. You’re also working on a book about color. Are there still color mysteries? Are there things science doesn’t know about color? 

There are lots of mysteries about color. For a long time, people thought that color was a little bit like a filter, that everything that’s really important is in black and white, and then there’s a color filter you put on top of it. 

But a bunch of years ago, my lab were blown away to discover that there’s as much brain involved in processing color as there is in face recognition.

The same amount of processing power?

Yeah, there’s tons and tons of tissue [and] pretty fancy bits of brain that are doing pretty high-level things — parts of brain we think of as being involved in social cognition and in high-level reasoning and visual memory. Color must be more than just this little add-on. It’s doing something much deeper. So we’re trying to understand what those bits of brain are doing.

So what is color? How does it work? How do our brains and eyes perceive it? 

The classic definition would be: Color is the visual feature that you get from wavelength properties of the light entering your eye. People typically see the long wavelength end as red light, and then going through short wavelengths, you know, following ROYGBIV: red, orange, yellow, green, blue, indigo, violet.

If color were just wavelength, then an object under blue light would look blue, and the same object under yellow light would look yellow. And that wouldn’t be very helpful — because what you want is a signal that tells you about objects, immune to the lighting condition. You want them to always have that color. 

A perfect example is a peach. If you look at a peach outside and you look at it inside, it’s always gonna look like a peach color. But if you looked at the pattern of wavelengths that are coming off of the peach, they’re very different under different lighting conditions. They should be different colors if color were just wavelength, but they’re not. Those two different compositions of wavelengths look the same color. 

What I think is so cool about color is it’s so fundamental for how we need to experience the world — but the mechanics of how it does it teaches us a lot about the brain.

What we’re talking about is color constancy. That is, an object’s color is constant despite the viewing conditions. 

So if the peach is fundamentally a different color inside and outside, and our brains are telling us that it is still, you know, peach colored, how are our brains deceiving us?   

So it’s not fundamentally a different color. It’s the same color. That’s the cool thing. The problem is that you are carrying around, Noam, in your head an idea that color is wavelength, and that is the mistake.

Color is not wavelength! And we’ve known this for a long time. But the problem is that we want something that is an empirical, measurable number that’s outside of an observer, that’s a thing out there in the world, that would be the same number regardless of who looks at it. And color, at its core, is not that. 

Color is dependent on your own visual system interacting with the world. And that doesn’t mean it’s any less real. It just means that its reality is dependent on psychological neural brain processes. And that’s what makes color fascinating. 

Color is, you’re saying, something that is essentially created in the brain. 

Absolutely, yes. Color is a generative product of the brain that gives us reliable, useful, true, meaningful, objective information, but it itself is not [those things].  It’s some generative product of  your brain in order to come up with this information that’s useful and meaningful about the world.

[Your brain is] actually creating that thing that is a color. Colors don’t exist out there in the world independent of a viewer to see them. 

Is this related to “the dress” — you know, like 10 years ago when that photo of a dress went viral, and a bunch of people on the internet thought it was blue and black, and a bunch of other people thought it was white and gold, and everyone got super upset? Is this the same type of thing, of seeing something in different lighting or different contexts and perceiving a different color? 

It is. So the dress was fascinating because people with normal color vision looking at exactly the same thing were asserting very different perceptions. 

And, you know, from a deep kind of philosophical point of view, it’s important because they weren’t saying, “Yeah, it kinda looks different to me, but I understand how you could see it as different.” They were like, “No, it is white and gold.” And other people were saying, “It is different colors.” That was, for me professionally and personally, a really big deal because it underscored this fact that color is this generative, constructive thing that your brain is doing, making all kinds of assumptions, filling in the gaps about lighting, about what you think you’re seeing.

In the case of the dress, it’s such a crappy little photograph, very blurry. It doesn’t give you a lot of context. And your visual system, your own brain, has to make a guess about what the lighting is. And if your brain guesses that the lighting is nice, warm, direct sunlight, then it implicitly subtracts out a little bit of the yellow from the image, and you see it as blue and black. Whereas other people looking at exactly the same pixels on the same monitor who assume that the lighting is cool, indirect, shaded light from blue sky, their brains color-correct the image, subtract out some of the blue, and they see it as white and gold. And so you have these two groups of people whose brains have just made different assumptions. 

Why do you think that left people feeling so unnerved? When this happened, people could not possibly believe someone else could look at that dress and see a different color. 

It was amazing! And, you know, it’s still, to date, I think, the most viral image in the history of the internet. Right when it came out, my initial reaction too was like, “Huh, that’s weird. I wonder what’s going on there.” And a lot of my colleagues thought, “Well, maybe it’s got to do with proportions of rods and cones, or people are looking at different displays, or maybe people are just silently color blind.” 

But I think the idea that your own brain could play such a fundamental role in determining what the pattern of wavelengths means, even for vision scientists, wasn’t sitting front of mind. 

I think the reason that it played so deeply, if I could wax poetic, it’s that our contemporary society depends on a shared experience, right? Our laws depend on a common idea of what’s right and wrong.

Yeah, like whether my red is your red; we still need to be able to point at something and agree that it’s red. 

Yes, and here was an example where it was like: “That isn’t white and gold, that’s blue and black, clearly. Do we live in a shared reality?”

And if you can’t trust your eyes, what can you trust? I think people genuinely felt like, “Is this the beginning of the end?” Like, “Is our whole society collapsing?” I mean, look at Twitter, there were all sorts of expletives flying around. 

Have you ever gotten into an argument about a color? I once got into an argument about tennis balls and what color they were. 

Yeah, what color are they? I’m curious. 

I couldn’t believe anyone thought they were yellow! I always thought they were green.

They’re totally yellow. I mean, we can get into one now. You’re wrong. It’s so funny — I really thought that they were definitionally yellow.

So what is going on with tennis balls? 

Tennis balls are funny. I mean, if you ask people to pick their best example of green and blue and red and orange and yellow and so on, there’s a lot of variability. Green and blue is the most variable. Some people’s best example of green is another person’s best example of blue. 

Meaning, you could ask me  to pick a color that would be perfectly green, and then someone else would be like, “No, that’s blue.”

Yeah, exactly. And this isn’t language-based. This is true across all cultures. 

We just perceive blues and greens kinda badly or vaguely? 

Yeah, and one of the ideas that we have about that is that blues and greens aren’t really the colors that are tied to objects.

So if I ask you what colors are objects, it’s a weird question! It’s like, objects can be any colors. But it turns out, if you actually go and measure, you know, the colors of things that you choose to label in the world, most of them are, like, yellow, brown, red, pink, some purples, not many.

Yeah, I guess green and blue is the background. Like green’s the forest, and blue is the sky. 

Yeah, exactly. And, and even in nature, there are very few natural blue objects, and that’s partly what made blue as a pigment so desirable. So what’s weird about yellow is that yellow, if you just ask people in the rainbow to pick where yellow is, people are incredibly consistent.

So people really know yellow. 

They really know yellow. And I think what’s going on with the tennis ball is that it is a little bit fluorescent. It’s actually emitting a little bit more light than it’s taking in because it’s reprocessing it, short-wavelength light in the visible spectrum.

So they’ve picked this bright yellow, which is right at the peak of our visual system sensitivity. So the color of the tennis ball is the optimal wavelength that we can detect with our eyes, and it’s right in that range where it’s technically probably closer to green than it is to yellow. But because it’s so bright, and yellow is considered a bright color, the brightest color, people could be persuaded to see it in a yellow direction.

What I hear you saying is that I’m right — and it’s green. 

Yeah, yeah. Although, I still like it as yellow.

There’s no place like Kansas, a state whose howling winds are so fierce that in the 1800s, the roaring soundscape drove local farmers into madness. It is so windy in Kansas that every so often, trains get swept off their tracks or trampolines get hurled into the air and flung into neighbors’ trees. 

But today, the same gusts that whisked away Dorothy’s home have made Kansas the third-most wind-powered place in the country, its great plains dotted with thousands of twirling turbines responsible for generating over half of the state’s energy. 

And for years, Kansas has been trying to share. 

But that’s easier said than done in the US, where building power lines across state borders can be an onerous, litigious, and bureaucratic slog. The Grain Belt Express, a proposed 800-mile high-voltage line carrying Kansas’s windy riches across Missouri, Illinois, and Indiana, has been trying to get built for the past 16 years. When completed, it will allow Kansas to pump five times as much wind power into Missouri as it does now. But though the project received its first approval in 2013, it will likely not open until 2029 at the earliest, beset by regulatory hurdles across multiple jurisdictions and an endless stream of legal challenges that immediately halt progress every time a new injunction is filed. Alas, the express — which only broke ground this year — was forced to run oh so local. 

But other projects like it might soon enjoy far more reasonable timelines. On Wednesday, a bipartisan group of Senators announced a deal called the Bipartisan American Affordability and Jobs Act, or BAAJA — an acronym that’s led to a slew of cringeworthy euphoric Baja Blast references from abundance Democrats, clean energy advocates, and oil industry lobbyists alike. If passed, it would significantly curtail Americans’ ability to endlessly litigate against energy projects they don’t like, and empower the federal government to push critical multistate projects forward even if one state or municipality drags its feet. That could remake the way the nation’s energy infrastructure gets built, including its interstate transmission lines, for decades to come. 

But the bill also suggests that easing the way for clean energy in the US may require simultaneously creating the conditions for more oil and gas infrastructure in a country that already has a lot of it. It would also mean defanging some of the landmark regulatory norms that for decades have, for example, given Americans a say over developments that could contaminate their drinking water and helped tribes protect sacred heritage sites. These laws were necessary in the first place because prior to the 1970s, American communities frequently found themselves both literally and figuratively steamrolled  by developers singularly focused on building things quickly with little regard for the oil spills, river fires, and bifurcated neighborhoods they left in their wake.

And yet today, half a century later, that same dilemma has, in some ways, turned on its head. America builds things too slowly, and in particular, it builds the kind of infrastructure desperately needed to usher in a transition to clean energy with little of the urgency you’d expect from a world in the throes of climate change-related disaster. Exasperatingly, some of the same protections that have played a critical role in making this nation safer may also be standing in the way of building a nation that is more affordable and sustainable in the long run.

There are still plenty of reasons to feel hopeful about the world’s transition away from fossil fuels, even in the US, which has lagged behind our peers while still building an extraordinary number of solar and wind farms, particularly in Republican-led states like Kansas and Texas. And yet, many of these projects have languished in never-ending Ticketmaster-esque queues to connect to the nation’s decrepit power grid, a direct result of the permitting hellscape that prevents much-needed high-voltage cables like the Grain Belt Express from coming online.      

This new bill aims to ease many of the bottlenecks that stymie clean energy, but it also throws a bone to fossil fuels, which, like renewables, would benefit from less onerous environmental reviews and quicker permissions. This is, after all, a bipartisan bill in a Congress that, at least for now, remains Republican-led, under the tutelage of an aggrieved president who has sabotaged some of the nation’s most promising clean energy projects with an often petty and relentless fervor. Some Democrats in Congress, along with other environmentalists, have raised serious concerns about the bill. Those initial objections may prophesize an uphill battle for it when it comes to a vote, likely after the November midterms. 

Even so, with American electricity bills spiking to frightening new heights, and a data center buildout that could all but snap the power grid in half, this ambitious deal is, at the very least, an indication that some of the nation’s representatives are finally listening. And if it passes into law in the months to come, it could very well remake how Americans get their energy for a generation. 

So why are environmentalists mad?

By most accounts, the Bipartisan American Affordability and Jobs Act almost didn’t happen. 

For months, the proposed permitting deal has been stalled by the Trump administration’s failure to assure Democrats that the president would lay off his attacks on “windmills” and other clean energy projects. But in recent days, lawmakers appear to have come close to a fragile détente on the back of a “very reasonable opening proposal” from the White House, according to Sen. Sheldon Whitehouse (D-RI), the ranking member of the Environment and Public Works Committee. 

If the BAAJA is passed, it will codify new protections that legally prevent presidents like Trump from meddling with already-permitted energy projects or singling out specific forms of energy, a prohibition that will also apply if a Democratic president attempts to halt an approved gas line or a petroleum refinery. The Biden administration’s freeze on approvals for new natural gas export plants, for example, would not be allowed. 

It’s this element of the proposed bill that worries many environmentalists most. According to a transcript obtained by Punchbowl News, during a coalition call on Thursday, dozens of advocates from prominent environmental groups — including the Sierra Club, the National Wildlife Federation, and the Environmental Law & Policy Center — expressed their misgivings about the bill and strategized about how to lobby Democrats against it.

Most environmentalists acknowledge, however, that we need to spruce up the power grid and fix how permitting works for clean energy projects and transmission lines. As clean energy advocates know all too well, the projects they support are, paradoxically, more likely to be hampered by environmental reviews than fossil fuel projects are, because renewables usually require more space and represent the bulk of new energy developments. But many advocates understandably take issue with the idea that reforming this overcomplicated process may require weakening the right to challenge other projects, a right affirmed by the National Environmental Policy Act, the Clean Water Act, the Endangered Species Act, and the National Historic Preservation Act. 

The bill’s fate may ultimately depend on whether this trade-off is worth it. The BAAJA still does leave some room for court challenges if they’re filed within 150 days of an approval. But it will still place a much larger burden for determining these damage thresholds on federal agencies, which are, of course, currently controlled by Trump.

“The question’s not whether that would be a good idea — it’s one of the basic building blocks for converting more of our energy system to renewables,” the environmentalist Bill McKibben wrote of grid expansion and permitting reform on his Substack this week. “It’s how many pounds of flesh the fossil fuel industry would demand in return, and how close to vital organs that flesh would be located.”

The problem is, no matter how many Congressional seats Democrats seem poised to scoop up in November, they will still need to get Republicans on board if they want Americans to be able to really see the benefits of solar, the cheapest energy source of all time, reflected on their power bill. And for most of the nation, if not Earth itself, that transition can’t come soon enough. 

Socialism is breaking through to the mainstream this year, with surveys showing most Democrats, and plenty of independents, now view the term positively. 

The shift is being led by young people in particular, who have also helped left-populist candidates win high-stakes primaries this year. A Cato Institute poll from June found that over half of Gen Z are more supportive of socialism (53 percent) than capitalism (45 percent). And more than half (57 percent) of people ages 18 to 34 have a positive view of socialism, according to a Gallup poll from August — versus just 34 percent of people over 55. 

Figures like these are inspiring socialist organizers and frightening Republicans, who are accusing Democrats of sliding into “communism” in their midterm messaging.

But here’s a little secret I’ve been hearing in the focus groups I run through my research, media, and strategy company focused on Gen Z — it’s not “socialism” that’s attractive to young voters. In fact, there’s little agreement on what the word really means. 

Instead, it’s the social policies these candidates are running on that resonate — things like affordable housing, healthcare, education, a higher minimum wage, and higher taxes on corporations and wealthy individuals.

All summer long, I asked Gen Z voters to define socialism. There was no consensus answer, but much less talk of “workers controlling the means of production,” as one 22-year-old woman from New Jersey referenced, and much more of a focus on what a 21-year-old man from Florida described as a “social safety net.” 

Understanding where they’re coming from is important to both critics and supporters: Revolutionaries and reactionaries alike who think young people are signing up for a specific ideology are misreading the moment. When it comes to the rise of “socialism,” young people want what they’ve always wanted: to be heard, and to be helped.  

Why socialism is resonating with Gen Z

Gen Z’s interest in the term was closely tied to the myriad ways their economic outlook has deteriorated in the past year. 

“I feel like over the last year things definitely have changed. You see it generally even with gas prices. … A lot of it has to do with the fact that our country has involved itself in a lot of different conflicts around the world at this point,” the 21-year-old from Florida said. 

“During the school year I am relying on my refunds from school to pay my rent, to pay my car payment and car insurance, phone bill, internet, stuff like that,” said another 21-year-old man from Pennsylvania. 

“I haven’t been able to financially plan for my education in the way I thought I was going to and have been needing to save more of my own money from jobs I’m working to help account for those differences,” said a 21-year-old woman from North Carolina. 

As economic anxiety reshapes Gen Z’s politics and life feels harder and harder to afford, young people are looking for the government to provide social support. 

Consistently, I asked groups of young people this summer what they’re looking for in an ideal political candidate — and the government more broadly. Overwhelmingly, they told me they’re in favor of politicians who understand everyday people and a government that provides social services for its constituents.

“A political candidate who understands the common person. Someone that’s not financially out of touch, who doesn’t take money from different corporations. Someone who understands the struggles of an everyday American and knows what’s going on with the economy and can understand the struggles of students, children, families,” said a 21-year-old woman from Michigan.

“Providing a higher safety net with welfare, especially with hospitals because of the ‘big, beautiful bill’ and its effects,” said a 19-year-old from New York City, citing the impact of the Trump administration’s recent tax bill that slashed healthcare spending.

“A candidate who isn’t afraid to say that we deserve more as citizens,” said another 19-year-old woman from Michigan.  

According to many of the young voters I spoke to, in their eyes, this is what socialism means: a more ambitious, generous, and equality-minded government. And when I asked them to tell me about the policies they associate with democratic socialists, they said things like “Medicare-for-all,” “help with college tuition,” and “social safety nets like healthcare, public education, public housing.” 

Where young people see socialism working

In pushing back against socialism’s rising popularity, critics often invoke history, pointing to Marxist governments where equality was instituted by force and coercion and associated with poverty and deprivation. 

“They’ve gone communist, but we’re not going to let that happen,” President Donald Trump said at a South Carolina rally in August. “It’s never worked in 1,000 years with different names, lots of different names. It’s never worked once.”

Just as Gen Z was presumed to be “woke” Democrats four years ago and then swung hard to Trump and MAGA in 2024, the socialist turn is just as conditional.

On the whole, however, young people I spoke to were less likely to tie socialism to “communism” or to places like Cuba, Venezuela, or Soviet Russia. Instead, they gave examples where they perceive socialism to work well, often mentioning wealthy Western countries and the social support systems associated with these kinds of governments.  

“I think Scandinavian countries and those countries have had socialist policies in place and people end up having universal healthcare and people are able to live more comfortably and receive more money from the government to support them,” said a 21-year-old woman from Massachusetts. “I know in Canada there’s some socialist policies that I think have benefited people in regards to healthcare and welfare and social security.” 

This shouldn’t be surprising. With years of distance from the Marxist governments that our parents and grandparents may think back to (even the oldest Gen Z were born well after the Cold War ended) young people are more focused on social policies than the core tenets of socialism. 

“The first thing that comes to mind is the government’s involvement in making sure that everybody is cared for and everyone’s health remains a priority despite their income,” said that 21-year-old woman from Massachusetts. “And I think that is something that makes me view socialism in more of a positive light because some people obviously don’t have the same financial situations as others. That doesn’t mean that they should be undervalued in society.”

Liking socialism doesn’t mean identifying as a socialist

But just as socialism’s detractors are misunderstanding its appeal among young voters, its supporters should be just as wary of assuming voters are signing up for their movement. 

I’ve heard anecdotes like the ones above shared over and over again. And yet, very few young people I’ve spoken to in the past few months have been willing to call themselves a socialist.

This is consistent with a broader Gen Z skepticism toward political parties. While they’re leaning into the policies associated with “socialism,” they still largely reject labels — whether that label is Republican, Democrat, or…socialist. 

Asked if she would consider herself a democratic socialist or a socialist, the 21-year-old from Massachusetts said she “would definitely lean that way.” A 19-year-old woman from Colorado said, “I would say I lean towards it, but I haven’t completely been with that party.” 

And a 23-year-old woman from Arizona said: “I would say I’m in between democrat and democratic socialist.” 

And while a 19-year-old from Michigan said she appreciates that democratic socialists are “going to help get baseline needs for people across America met in ways that aren’t going to happen if we have someone who is taking money from PACs and corporations making money off of people going into medical debt and things like that,” but asked if she would label herself that way, she said, “I feel like I don’t know enough about it.”

This isn’t universal. Polls suggest a sizable number of young Democrats identify as democratic socialist when asked. But when it comes to organized political behavior, the Democratic Socialists of America only recently passed 120,000 official members, even as they’ve had unprecedented success in raising their profile and nominating candidates this cycle.

Just as Gen Z was presumed to be “woke” Democrats four years ago and then swung hard to Trump and MAGA in 2024, the socialist turn is just as conditional. They’re looking for concrete solutions, not dogma, and if they don’t see results, they’ll look elsewhere.