Emerald crab turning purple?

[Nem0]

I noticed my emerald crab's back legs have turned a bit purple. when i got him, they were all green. the color looks similar to the red slime outbreak I've been having...but i don't think red slime would be on an invert? none of my other CUC have it on their shells

picture isn't the best quality, ill try and get another one if he comes out

 

[Jon Fishman]

I believe they change color as they grow. I may be wrong though. I have emeralds of various colors.

 

[Nem0]

okay. ill keep an eye on him nonetheless

 

[Nem0]

here's another pic