Cat likely has a genetic condition
All species are subject to the occasional genetic quirk, which can result in an all-black jaguar or an albino human or whatever. This case is uniqure: no one has ever seen a pink-coated leopard before. It may have a condition called erythrism that can result in an excess of red pigments. Otherwise, the leopard seems fine, and the odd coat hasn't kept him from hunting successfully. Just a reminder that Nature's card deck occasionally deals a really strange hand.