A standard tennis ball is officially a bright yellow, more precisely called “optic yellow,” which many people see as yellow with a slight greenish, lime- like tint.

Quick Scoop: What colour is a tennis ball?

Most people, and the sport’s official rules, treat the answer as yellow.

However, the exact shade—“optic yellow” (#ccff00)—sits right on the border between yellow and green, which is why online forum debates keep resurfacing about whether it looks more yellow or more green.

Why “optic yellow”?

  • Modern tennis balls switched from white to yellow in the 1970s because tests showed yellow was much easier to see on TV and across different court surfaces.
  • The International Tennis Federation only allows yellow and white for official balls, and the yellow used is a highly visible fluorescent tone to stand out at high speed.

So why do some people say green?

  • Human colour perception varies a lot from person to person, especially around the yellow–green boundary, so some brains label the same hue “green” and others “yellow.”
  • The specific “optic yellow” used in tennis can be described as a cool yellow with hints of green or as a very yellowish lime, which fuels the ongoing arguments in forum discussions and social media threads.

Other tennis ball colours you might see

  • Training balls for kids and beginners often come in red, orange, and green, each slower and lower-bouncing to match different learning stages.
  • Recreational or novelty balls can be white, pink, blue, or black, but official competitive play still revolves around that iconic optic yellow.

In short, if you are asking “what colour is a tennis ball” for rules, TV, or official play, the accepted answer is yellow—specifically optic yellow—even if your eyes keep insisting it looks a bit greenish.

TL;DR: Officially yellow (optic yellow), perceptually sitting right between yellow and green, which is why the internet never agrees on it.

Information gathered from public forums or data available on the internet and portrayed here.