Remember last year's "What color is the dress?" Yes, the illusion made everyone's head hurt. Get ready for another head-scratcher, er, eye-rubbing, follow-up with the colored hearts illusion.

Just like the dress, it all starts with a simple question: In the image below, what color are the hearts?

heart optical illusion Don't doubt yourself; just blurt out what you see. (Photo: Bite Size Psych)

If you answered two colors, purple and orange, you're correct — but only because that's what your eyes and brain want you to see. In reality, once the overlaid stripes are removed, the hearts are all the same pink color.

What sorcery is this?

As the narrator in the above video from Bite Size Psych explains, the stripes are composed of blue and purple, and when those stripes are placed in close proximity to the pink hearts, they fool our eyes into merging the colors.

"This gives us a vital clue on how our vision works," the narrator says. "It suggests that we perceive an object's color not based on its actual color, but on how it compares to the surrounding colors."

If you really want to test this illusion for yourself, take a look at the original, high-quality image here, open it in Photoshop, and compare the colors of the underlying hearts. Strangely, you'll find them to be exactly the same!