Boa Phases

In doing my boa research I have seen lots of pictures and sometimes the caption states that the boa is in its blue phase or its black phase and whatnot. I understand that its pretty obvious why its called that phase but I am not as sure about the actual phase changes.

Why do they change phases?
How often are they in a phase?
What happens to their temperment/feeding responses in different phases?
Does husbandry need to change for different phases?

I'd understand if nobody wants to type out a real guide on this but if somebody wants to point me in the right direction it would be very helpful.

Im used to 'blue phase' meaning the blue phase of shedding; the phase just before the actual shed. I dunno if it's meant to be any different for boa's though lol, sorry

"Blue Phase" means that the boa (or any snake in general) is going into shed, the blueish liquid builds up under the eye.

Boa's do go through other color phases as well though. Sometimes my normals and hypo's look lighter/darker than usual, either more speckling shows up, or they look completely clean.

I havent noticed any color change at all in my albino, she always looks exactly the same, no matter what.