A non-oxidative hair coloring composition, comprises yogurt or yogurt-derived material. The invention also provides a method of improving the coloring effects of non-oxidative hair coloring compositions, comprising application to the hair (during or after dyeing) of yogurt or a yogurt-derived material. The invention also covers use of yogurt or yogurt-derived material in a hair care composition for the purpose of improving the coloring effects of a non-oxidative hair dye. The invention can be put into effect by incorporating yogurt or yogurt-derived material into a hair care composition for use during non-oxidative dying of hair (i.e. a non-oxidative hair coloring composition) where it acts to improve dye deposition onto hair, or into a composition for use on hair after dyeing by a non-oxidative method, e.g. a shampoo or conditioner composition, to help maintain the color of dyed hair.