Hand turned color?

[abrink]

See below picture, not sure how this happened but I only have one theory.
Theory is that I was doing weekly testing (all tests in TF100) and spilled something on my hand.
I didn't notice until we were actually swimming though, so maybe something in the pool water reacted to it?

Soap doesn't take it off, I'll try some something stronger later. Anyone have any guesses as to if my theory could be accurate?

 

[Richard320]

It could be the FAS-DPD powder. Look what it did to my box!

 

[Killer95Stang]

Did you a salt drop test? That test turns my hand purple every time I use it.

 

[abrink]

Indeed I did, and I dumped it out into my hands to fetch my speedster magnet. I will stop doing that!

 

[chem geek]

The salt test uses silver nitrate and silver stains skin badly in a way that it won't wash out. It doesn't immediately show up and is absorbed into the skin, but exposure to sunlight then darkens it (just like in B&W photography where the silver ions get reduced to metallic silver). See this video for some bad stains and this video for the darkening of silver chloride.