Paint was a liquid or semi-liquid substance used to colour other objects or create artwork. It was also used to refer to the act of using the substance to colour other objects or create artwork.
Wilfred Mott used a paintball gun to attempt to blind a Dalek by shooting it in the eye stalk. However, the effort proved useless when the Dalek promptly vaporised the paint, clearing its vision. (TV: The Stolen Earth)
Giuseppe di Cattivo used the minerals from a sentient meteorite as pigments for his paint. It was used by him to create The Abomination, and lent some of it to Leonardo da Vinci for one copy of the Mona Lisa. (TV: Mona Lisa's Revenge)