What colour do you think these tennis balls are? - BBC News
Tennis ball - Wikipedia
How tennis changed from white to yellow balls thanks to David Attenborough - Tennis365
Tennis ball wasteland? Game grapples with a fuzzy yellow recycling problem | CP24.com
TIL Yellow tennis balls were invented by David Attenborough. In 1967 when he was controller of BBC2, he had the job of introducing colour TV and suggested switching from white to a