I wouldnt mind having altered colors for the HUD as some times I loose track of things on it due to the maps colors. I honestly would prefer an active HUD which changes colors according to whatever I am looking at. So if I am looking at snow the HUD has parts in black to be an easy read, then if I go to looking at a gunmetal blue wall it changes to have a gold or brighter color so things show up easier.
I know it will never happen as movements are too fast to track but there it is.