A tint is a shade or type of color. You might describe ocean water during a storm as having tints of green and gray.
After you play with your dog in the snow, your cold cheeks might take on a tint of pink. And an artist might change the color of the sky in a painting with a tint of purple. Tint is also a verb, meaning "shade" or "color very slightly." So rinsing beets will probably tint your white sink. Before it evolved into tint, the word was tinct, from the Latin tinctus, "a dyeing."