HCA: Hermit Crab Association

Hello. I had my first straw molt this week. I had experimented with some second level shelving that within days caused a mold out break. So I had no choice but to do a cleaning. During that cleaning a found him. He is a jumbo. From what I can tell he had just molted. It looked like most of its exo was still there. I took him and his exo and ISOed him in a little plastic caddy, inside of the main tank.
Anyways I'm curious about color and when to let him out. He looks dark dark pinkish purple almost black in some areas. Is that normal? And he is not under the sand. I did see him munching on some exo today. How long should I wait to check him out?
Thanks!

You should pretty much let him out about the time when the exo is fully eaten, or mostly eaten, and when you see that the crab seems to want to get out of the ISO chamber (being restless, walking back and climbing all over the plastic caddy). I think that would take about a week or so, if not more.

I'm not sure about the color issue, sorry.