The chick was...
Pinkish -- far as I know, every newborn chick is, and the question doesn't ask on what date the color was visible. This answer is unsatisfying as it does not use all parts of the setup.
Black-and-white -- emperor penguins lay eggs onto their own feet, and while they are biologically flightless, the child can take flight if taken by researchers or hunters on a helicopter: nothing said the bird was alive on its first flight.
I eliminated these answers, since they do not provide a single identifiable color:
Any color -- parent was simply not looking at the time of nest departure.
The plumage color of a juvenile Cuckoo, Cowbird, Black-Headed Duck, Weaver-Finch, Honeyguide, or other brood parasite (see accepted answer).
The plumage color of a juvenile non-nesting, ground-laying bird, such as the Nightjar, Plover, Killdeer and Short Eared Owl.