How do you know When it's in shed?

Just curious how you can tell when the RTB is about to shed?

I went to feed mine last night, and it wasn't even interested in the prey, just me and he tagged my finger. He's never done this before and always been very gentle. Everything is correct ( humidity, temps, etc ) so i'm thinking he may be ready to shed....he's alot darker than usual, but i'd imagine he should get alot lighter?

Thought i'd ask? He was also very active last night after he did eat, usually he just chills?

They usually turn dark then blue then clear up and shed.

It varies by snake I think. I can hardly tell at all with my hog island for example but with a dark one like the nic, its noticable to even the unexperienced eye. Usually you will see the colors dull like with most snakes.