Why Are Tennis Balls Yellow? The Story Behind the Sport's Most Familiar Colour

Pick up a tennis ball and you already know what it looks like before you glance down: that bright, slightly fuzzy sphere in a colour you have seen ten thousand times. It is one of the most recognisable objects in all of sport. Yet the ball has not always looked like this, and the reason it does today has almost nothing to do with tennis and almost everything to do with television.

What colour is a tennis ball, actually?

Ask a room full of people what colour a tennis ball is and you will not get a clean answer. Some will say yellow without hesitation. Others will insist, just as firmly, that it is obviously green. Both camps feel certain, and the argument has flared up online more than once as one of those disputes nobody can seem to settle.

Here is the twist: everyone is a little bit right. The official name for the shade is "optic yellow", the colour the International Tennis Federation settled on decades ago. But that shade sits right on the boundary between yellow and green on the spectrum. Under the Pantone system it falls within the green-yellow family, closer to a "safety yellow" than to the yellow of a lemon. So if you say green and your friend says yellow, you are both describing the same thing honestly. The ball was engineered to sit exactly where human eyes pick up brightness most easily, which is why it seems to almost glow against grass, clay or a hard court.

Why are tennis balls yellow?

For most of the sport's history, tennis balls were white. Occasionally they were black, chosen simply for whichever contrasted better with the court behind them. Nobody was thinking about wavelengths or visibility. A white ball on a green lawn was perfectly easy to follow when you were sitting courtside or watching in black and white.

Then colour television arrived, and it created a problem. On the new colour sets of the late 1960s and early 1970s, a white ball was surprisingly hard to track. It smeared against the pale lines of the court and washed out under bright light, so viewers at home kept losing the flight of the ball. Broadcasters and the sport's governing bodies took notice. Research showed that a bright yellow-green ball stood out far better on screen, because that part of the spectrum reads as brighter to the human eye than almost any other colour, especially on the televisions of the day.

So in 1972 the International Tennis Federation formally added optic yellow to the rules, allowing the new high-visibility ball into the professional game. The change was made for the people watching at home as much as for the players on court, and once you know that, the colour makes complete sense.

Did David Attenborough really have a hand in it?

There is a lovely piece of British broadcasting folklore attached to this story. In the late 1960s, a young David Attenborough was Controller of BBC Two and had the job of overseeing the channel's move into colour, which included the first colour broadcasts of Wimbledon. The era he helped usher in was exactly the one that exposed how poorly a white ball showed up on colour screens. It would be a stretch to say Attenborough personally chose the colour of the modern tennis ball, but the switch to colour television he championed is a big part of why the ball changed at all. It is a neat reminder that the look of the sport we take for granted was shaped by the technology of the living room.

Why did Wimbledon wait until 1986?

If the ITF approved yellow balls in 1972, you might expect every tournament to have followed at once. Wimbledon, true to form, did not. The All England Club kept using traditional white balls for another fourteen years, finally switching to yellow only in 1986. For a tournament that still enforces its all-white clothing rule and guards its traditions carefully, holding on to the white ball for over a decade after the rest of the game had moved on feels entirely in character.

A few more things you probably never knew about tennis balls

Once you start looking closely at the ball, it turns out to be a small marvel of engineering, and it hides a surprising amount of history.

Take Wimbledon again. The Championships get through around 55,000 balls across the fortnight, all supplied by Slazenger, whose partnership with the tournament dates back to 1902. That makes it the longest-running sponsorship in tennis, and possibly in any sport. The balls are not used until they wear out, either. A fresh set comes in for the warm-up and first seven games, and after that they are changed every nine games, because a ball that has lost its fluff flies faster and lower than a new one.

That fluff is not decorative. The felt nap on the outside of the ball creates drag as it moves through the air, slowing it down just enough to keep rallies playable and giving players something for their strings to grip when they generate spin. Underneath the felt sits a hollow rubber core filled with pressurised air, which is what gives a new ball its lively bounce. It is also why a fresh tin hisses when you open it, and why balls go dead after a few weeks of play once that pressure escapes.

Does the colour actually matter for your Saturday morning game?

For club and recreational players the answer is a quiet yes, even if you never think about it. The whole point of optic yellow is visibility, and that pays off most in exactly the conditions weekend players face: flat winter light, a low sun, or a dusk match where you are squeezing in a final set before the light goes. A bright, fresh ball is easier to pick up early, which gives you a fraction more time to set your feet and swing.

It is also worth knowing that not every ball is the same beyond its colour. Pressurised balls give the crispest bounce but fade after a few sessions, while pressureless balls last far longer and suit ball machines and coaching baskets. There are slower stage balls in red, orange and green for children too, designed to bounce lower while players learn. If you want to match the ball to your surface and level rather than grabbing whatever is nearest, our tennis balls buying guide walks through the differences, and you can browse the full range of tins of tennis balls whenever you need a fresh set.

None of this changes how the game is played, of course. But there is something satisfying about knowing that the little yellow ball in your hand carries a century of history and a clever bit of colour science, all wrapped in felt. The next time someone tells you tennis balls are green, you will be able to smile and tell them they are not entirely wrong.