© John Frieda

Semi-Permanent Colour*, or shampoo-in colour, adds colour and shine without changing your base shade, as colour pigments are deposited over your natural pigmentation.  They don’t contain ammonia, but use oxidising agents instead, which slightly open the cuticle, so that the colour can penetrate the hair.  Can be applied to coloured or treated hair and will usually last a limited number of washes.

Advantages: A subtle effect, especially if you choose a shade close to your natural colour.  Useful for covering first grey hairs, it should last around six to eight weeks.
 
*You can also buy hair tints and mascaras which are painted onto certain strands, lasting anything from a few hours to a few days, for a temporary change.