You asked a great question!
You are thinking, perhaps, of carotene or beta-carotene, the orange pigment in carrots and some other plants.
Keratin is a protein substance produced by the body. Different types of keratin form your hair, skin and nails.
Sue

PS - Trivia for the day - keratin also forms the shell of a turtle or tortoise, the scales on a fish or a snake or the horns on a bison or a steer. (But not the antlers on deer or moose - those are bones!)