I know, I promised we would never talk about The Dress again. I’m sorry. I lied. Because there’s a new optical illusion in town, and this time it’s a shoe.

Yes, The Shoe has been making the rounds on the internet, ever since someone called Nicole Coulthard published it on a Facebook group called Girlsmouth this week.

She said she saw the shoe as pale pink and white, but her friend said it was pale blue and grey. And thus, here we are.

“Ok girls so my friend has just sent me this asking what colour the shoe is, I would say pale pink and white, but she insists its pale blue and grey,” Coulthard posted on Facebook. “What do you girls see? Please tell me pink and white!”

In the IFLScience office, the majority of us see the shoe as pale blue and grey, but plenty of people online have been reporting both colors. And several pointed out that it was likely actually pink and white, as Vans – who made the shoe – didn't have a grey and blue version.

 

Speaking to the Metro, Coulthard said her friend had bought the shoes a few weeks ago and sent a picture to her mom, who said the blue color suited her.

“She texted back saying they are pink mum, but when she looked at the pic she saw blue too,” she said. “She sent it to me and I was convinced they are pink, we had a big argument as she said I only said pink because I knew she had bought pink shoes so that’s why I decided to put it up on Girlsmouth.”

Do we know what’s going on here? Well, sort of. You might remember last time we covered The Dress, a researcher called Pascal Wallisch from New York University said the time you woke up – and hence the amount of light you'd been exposed to – affected whether you saw the dress as black and blue or white and gold.

In his study, Wallisch showed that early risers were more likely to see white and gold, while people who stayed up late were more likely to see black and blue. Although not true for everyone, he said there was a pretty decent correlation.

“The same thing seems to be going on as with the dress,” he told IFLScience. “However, one key difference seems to be that people are much more easily able to toggle the percepts here.”

Sure, it’s a bit silly, but it’s a cool effect that is actually quite tough to explain. I’d like to say this is the end, but there will inevitably be more illusions inspired by The Dress. I can only apologize.