WhiteShirt Tetra Sun Tan?

[Fishery]

Hi all.

Just something i've notice over the weeks with a couple of the fish in the tank.. i've include a picture.

Are these markings just Tan lines or something more sinister?

I have a Balloon Molly that shows the same tan line but only along the edge of its tail fin.

 

[bravefish90]

I've seen this on fish in my shop. but can never figure if it's just the lighting or what. I'll be sure to ask my boss on the next work day.