Re: chameleon cat!
Welcome to Cat Forum.
The most logical explanation is pointed cats' hair-coats are temperature sensitive, being darkest over the areas that are the coolest and lightest over areas that are the warmest. Your new cat could be getting a layer of fat, living in a different temperature environment than the shelter had, be under less stress and allowing for a lower blood pressure and more blood flow and/or better food is helping to enhance the colors, so the paler markings are more visible. The kitty also could have 'white spotting', which is just white markings.
Anyhow, welcome to the forum. Got any pics?