While Democratic presidential candidates Hillary Clinton and Bernie Sanders debated everything from immigration reform to government bailouts on March 9, there was one controversy that blew up on Twitter that didn’t get addressed on stage: The color of Bernie’s suit.

Sparking a social media frenzy reminiscent of #TheDress in which millions debated whether the striped dress was white and gold or blue and black, people on Twitter questioned whether the Vermont senator’s suit was blue, brown, or black; some real radicals even suggested eggplant.

It wasn’t long before someone set up a Twitter account to speak for the suit. (The suit claims it is brown).

Even the Sanders campaign’s rapid response team had trouble pinpointing the hue, first calling it blue–a claim that was subsequently corrected by director Mike Casca who tweeted that the suit was in fact black.

The color controversy

Why does a simple black suit present itself so differently to so many viewers? One might suggest it’s been hanging around politics too long. But science tells us that perception of color in the real world is dependent on a variety of factors including the physical property of an object, the time of day, and natural variations in how each individual pair of eyes sees color wavelengths. Some neuroscientists even suggest there may be no colors at all and what we see is actually a figment of our imaginations.

Britain Dress of Many Colours The two-tone dress, left, alongside an ivory and black version, made by Roman Originals, sparked a global debate on Twitter. Photograph by Joe Giddens — AP

On television, an artificially lit environment that gets captured by a camera and transmitted to a wide variety of technologies to the viewer, the color of fabric can appear in many shades because of all the channels the color wavelength must go through before it hits the eye. In other words, seeing color on television depends as much on technology as the eye of the beholder.

Male candidates’ dress a distraction

This wouldn’t be male candidates’ clothing got attention. In 1960, for instance, when John F. Kennedy and Richard Nixon squared off in the first televised presidential debate, Kennedy’s suntan and dark blue suit were in sharp contrast to Nixon’s pale face and five o’clock shadow. The Republican also had chosen a pale gray suit, which only served to enhance his ashy complexion and prompted Chicago’s Democratic mayor Richard J. Daley to comment, “My God, they’ve embalmed him before he even died.”

For male candidates dark blue and charcoal gray have traditionally been the exclusive choices when it came to suits — that is, until Ronald Reagan “changed the direction of fashion,” by wearing a dark brown suit on important occasions.

President Obama has been a proponent of a “uniform” of gray or blues. (“I’m trying to pare down decisions,” the President told Vanity Fair.) But even Obama needed to mix it up a little stepping out in a light tan suit for a foreign policy discussion focused on ISIS. Even though it was appropriate for the summer season, critics contended that it was a mistake. “It was a somber occasion, and there’s apparently a certain expectation of precisely how the President’s attire should match the mood,” a TIME reporter wrote.

Whatever the color of Sanders’ suit, one Twitter user noted that at least it’s the male candidate’s clothing choice that’s under scrutiny for a change.