Marbled Crays

[apistofishguys1]

One of the full grown adults just turned an electric blue color in about two days. Another one is starting to turn brick red. Anybody know what causes them to change these colors?

[Nabobmob1]

The one I got from you is red with blue claws

[Underwhelmed]

Mine is still normal coloration.

I read a bit about marbled crays changing color, but it was not conclusive. Some said water, others said diet. It seems in some cases it changes by molt, so the coloration is not always fixed.