There are other things affecting color too.
On bones, if the chicken was semi to fully frozen, it causes the bones to turn color from purple to black. Even a hard chill can do that (hard chill refers to bringing the temp down to 31° - 32° and holding it there for extended shelf life and transportation.). Hard frozen chicken does that also - when you get down to the bones, if they're black, the bird has been frozen and thawed. Of course, freezing bursts cell walls from ice buildup and the meat purges - liquid drains out. That contributes to dryness; moisture cannot be held in.
When a chicken is killed, the blood must drain out. It is quite common for the blood to pool in the joints and can cause a pinking of the meat. Also, chickens go through a bath - chicken soup - and sodium is added, much like curing, and that can cause pinking also. Combination of blood and frozen/thawed causes many of the conditions noted.
And, of course, get good therms so your knowledge of the meat temps is accurate.