The Colour of Tennis Balls???

[Trevor.Dennis]

This article comes from BBC News today, and is just barely on topic for this forum.   It appears that a lot of people are not sure whether tennis balls are yellow or green, but folk like us know that those colours are closely related.  If you want to darken the grass or foliage in a picture, we use the yellow sliders and not the green.  Other people argue that if tennis balls were green, then they would be hard to see against the grass at Wimbledon.

I would say that the yellow in the centre of these balls, clearly trends towards green on their periphery. Incidentally, I did of course spit after pasting in this Getty Images stock image seeing as they are responsible for making it so difficult to grab images from the internet nowadays

What colour do you think these tennis balls are? - BBC News

At the end of the day, the numbers don't lie.  Sample point #1 has equal levels red and green, and no blue, so is unarguably yellow.

Sample point #2 has half as much red as it does green, and still no blue — is there a proper (posh) word for yellowy green?

[Norman Sanders]

A Google search (a sign of just how busy I am) turned up the official color of tennis balls. It turns out that its official name is either Optic Yellow or Fluorescent yellow and the Lab designation (in round numbers) is 94, -42, 90. The trouble with those numbers is that a monitor cannot present a fluorescent color. No dazzle. Add to that the fact that true fluorescent ink colors are opaque which limits their use. But, for what it's worth, here is the color in sRGB mode. Don't shoot me, Trevor. I am only the messenger.

[Chuck Uebele]

Yea, I saw this report on the TV this morning. Gauging the color of something in a photo is crazy, especially something like this, or putting up something that is cyan and asking if it's blue or green. Good thread on the topic from 2004:

Tennis ball color theory — Digital Grin Photography Forum

[Trevor.Dennis]

It has never occurred to me that tennis balls are so similar in colour to florescent clothing.  I wonder if it is just the colour, or if there is something in the dye to make them reflect light more efficiently?  From our point of view, it is the difference between what we can see on a screen, what a printer can print, and having the actual object in front of you.

There is no doubt that safety clothing stands out, and I believe that yellow is the colour the human eye is most drawn to, which is probably why landscapes like this are so appealing, Well they are to me at least

Puru Bob  wrote

I preferred orange balls in the days when I played tennis.

Woah Bob.  That definitely falls into the category of too much information!  

[D Fosse]

Pretty simple, it's yellow-green. This is the exact wavelength where the eye's sensitivity is highest.

Out of gamut in sRGB, probably just in-gamut in Adobe RGB - depending on how close it is to the green primary. But most solid surface, reflected light color is within Adobe RGB. There could be structural properties in the tennis ball "skin" that pushes to higher than normal saturation.

The color in these photographs is full of artifacts, as it usually will be when you push saturation right to the gamut boundary, with unpredictable clipping effects. Any measurements off that are meaningless.

[Semaphoric]

I thought this was going to be one of those "What color is this dress?" things.

Here's a blog post about how Mirriam-Webster (the dictionary people) get their definitions for various colors: Color definitions: Their history and why it's so hard to define cerise, taupe, blue, begonia, or any...

[Peru Bob]

I preferred orange balls in the days when I played tennis.