Gray Cover is a unique formulation to enhance the penetration of colour into the hair by boosting the coverage of the most stubborn grey hair. It boosts the action of any dye on the market, increasing the coverage power to the maximum, either due to a large amount of white hair or due to a resistance to absorption of the hair to be coloured. Covers even the most difficult grey hair. Allows for greater coverage. Compatible with all dyes on the market.