Found in Southeast Asia, adult Phayre’s Leaf Monkeys (Trachypithecus phayrei) are completely grey and their newborn babies are bright orange. This clip is from the BBC’s Life documentary series, written and narrated by David Attenborough.
The advantage to having such conspicuous colouring is that it makes it easier for their parents to keep an eye on them and it’s not just the parents. Close friends and relatives are eager to help too, with the result that a baby is rarely left on its own for long. After a few months, however, when it’s more independent, the young one will turn grey and blend in with the rest of the group. But until then, it can’t be ignored.