Celebrities brought back the sneaker optical illusion. We're not thrilled

A tweet that sparked debate in 2017

(CNN)Think about it: For two whole years, we had managed to peacefully carry on with our daily activities without angry-tweeting at strangers about the color of a pair of shoes.

That glorious time is over.
*Sigh*
That debate is back after two stars posted the image on Instagram asking for their fans' responses.
    "I saw this image online and I showed it to a bunch of people and it's really, really spectacular, what comes back," Will Smith said in a video this week. "What color do you see? Now show ... whoever is around you ... and ask them what color do they see and I think you'll be surprised at what the answer is."
    View this post on Instagram

    Which colors do you see?? 🧐

    A post shared by Will Smith (@willsmith) on

    "There's no right answer but it's definitely not pink," he says.
    In another video, he's seen arguing that the shoe is green and gray. Others in his group say they see pink and white.
    Singer Lizzo was apparently having the same dispute.
    "I see grey & teal but my whole team sees pink & white help," she posted on Instagram.
    The famous shoe color debate was one of two optical illusions that took over the web in the past years, pinning friends and families against each other over the difference in the colors they perceived.
    In 2015, a (white and gold) dress had people going crazy. Many thought it was blue and black.
    One eye expert said it all has to do with how we each perceive lights and colors depending on our genes.
    "It has to do with the tiny cones in the back of our eyeballs that perceive colors in a slightly different way depending upon our genes," CNN's Senior Medical Correspondent Elizabeth Cohen explained during the infamous dress debate.

    By the way, there's a right answer

    Maybe we'll never find out what color the dress really is, but the woman who first posted the shoes on Twitter said they were actually pink and white.
    The whole thing started when her friend's mom saw the photo of the shoes and said there was a blue hue, the woman had told Metro UK two years ago.
      A Twitter user tried to clarify things by saying the darkness of the woman's original photo skewed the colors and posted a second photo with less contrast. That didn't help at all. The photo circulated and had the internet world divided and confused.
      So there you have it: biology, contrast and badly taken photos.