Has anyone ever seen reliable gray cards in sticker form?

So it appears that I'm likely to be shooting with a group playing roller derby in an arena with fairly awkward lighting, which has an annoying habit of shifting colour depending on what part of the building you're in. It made post a whole lot slower, and I haven't actually bothered to balance them well yet and decided to just do extra edits by request. However, it did give me an idea that would make things a whole lot simpler. Just stick a pile of small gray cards on everyone's gear to make it easier to match up white balance on each one.

However, after a bit of googling I'm getting the impression that either this idea really doesn't work well at all, no one has really tried it, or it possibly works well but people are using some non-photography related product for the task.

Any ideas or suggestions on how to easily include patches of a balanced neutral material suitable for a colour target to player's uniforms? (Players in question are wearing roller skate gear, so lots of helmets and flat parts of pads to reliably stick things to.)

How about just some little white sticker dots like price tags, and make sure not to overexpose so the dots are clipping?

I know what you mean though, the last place I shot roller derby, the lights inside the dome were sodium vapor (or something) that didn't make a full spectrum of colors, and on the West and North sides they had big doors open to the outside afternoon sun. With some teams, you can use the star on the jammer's helmet or the stripe on the pivot's helmet - those will usually get you pretty close, depending on the type of fabric.

And the stage where my wife's dance group performs, they have colored stage lights, and a spotlight that often has a colored filter over it. Blue, green, red...ugh! Most of those just get converted to B&W.

Great idea. All leagues, including NFL, NBA, and MLB, should require a gray stripe on all uniforms. I would support that.

I've learned that you are just looking for a neutral color in a Lightroom class with Jared Platt. He recommended using something black in the photo to "white" balance from. I've tried it on baseball photos shot under lights and it works. I tested balancing from black and balancing from white in the same photo and the black worked better 90% of the time for me.

I have been mostly using blacks, but the problem is some of the gear seems to not be 'black', but rather very dark purples and blues, and I was mostly just looking for a way I could spend a few bucks and slap some known indicators on the gear to go by.

bpalermini wrote in post #14656997
I've learned that you are just looking for a neutral color in a Lightroom class with Jared Platt. He recommended using something black in the photo to "white" balance from. I've tried it on baseball photos shot under lights and it works. I tested balancing from black and balancing from white in the same photo and the black worked better 90% of the time for me.

This might be because the white that you were using was blown out? If the black was compressed to 0, 0, 0, then it wouldn't work either.

Photosguy is correct. White works best for white balance, as long as it's not overexposed. The real problem is finding something truly white to click on.

For sports shooting I usually look for white socks or a white stripe on the uniform. It doesn't work perfectly, but it gets me in the ballpark and I tweak things from there.

The real problem with gym lighting is the cyclical nature of the putrid sodium vapor lights. Like fluorescent lighting, they'll give you a different white balance on every shot.

If I'm hard up...I'll use a piece of duct tape...close enough for goverment work.