Color fading on orange cat

My girlfriend just got her two cats back, One male one female. The male is about 6 years old and we've noticed a real loss of color in his orange coat.. Also, his testicles have a dark discoloration. They're black to be honest.. The female is overly aggressive to the male, my girlfriend and myself. This is something my girlfriend says she has never seen in her before. Has anyone had experience with either of these kinds of symptoms? I've been looking for a while and I can't find any answers. Thank you.