Do you think a tennis ball is green or yellow? Or do you think it's a completely different color?
You probably have never had an argument with someone over the color of a ball, but a recent Twitter poll has the world divided.
Twitter user CGP Grey wrote, "Please help resolve a marital dispute. You would describe the color of a tennis ball as: green, yellow, or other."
After almost 30,000 votes, 52% of participants said the think the color of a tennis ball is green, while 42% voted yellow, and 6% voted other.
I think tennis balls are yellow, but there are a lot of people who see it as green, or a different color. Some Twitter users wrote they think these balls are a "greenish yellow."
Apparently there is one right answer...
According to the International Tennis Federation, the tennis balls you see today are yellow. The color is said to have been taken from the Isaac Newton color wheel, which is a theory of color. It's believed that red, yellow, and blue are primary colors which all other colors are derived.
So the reason why people see tennis balls as green, yellow, or both, is because these colors can have a very similar hue. If you look at the Munsell Hue Circle, you'll notice that yellow and green start to overlap at some point.
Tennis balls aren't the only things that make you want to scratch your head in confusion. Other objects that have a special hue can be seen differently in different lighting conditions.
The same thing happened when everyone got worked up over the color of "The Dress." Was it white and gold or blue and black? Turns out, the dress wasn't white at all, but it all depends on your unique visual perception, according to Bevil Conway, a neuroscientist who studies color and vision at Wellesley College.
"Most people will see the blue on the white background as blue," Conway told Wired. "But on the black background some might see it as white."
The same goes for how we see a tennis ball!
Jeff Ratkovich, senior business manager for Penn, one of the world's largest tennis ball manufacturers, told Metro: "The color of a tennis ball is relative to what it's compared to. If you hold a tennis ball up to something green, it looks more yellow, and if you hold it up to something yellow, it looks more green.