Colouring agents (4)

I believe the answer is:

dyes

(Other definitions for dyes that I've seen before include "Stains" , "Colouring materials" , "Substances for staining or colouring" , "turns green, possibly" , "Many a pigment" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.