Color Refresh contains semi-permanent color pigments that stick to the outer cortex of the hair - this means that the color does not penetrate as well as a permanent color. Depending on the starting point of the hair, the color gradually washes out between 4-10 times (sometimes it takes longer if the hair is very porous). Please note that when used on grey or untreated hair the results may vary. Since it's only temporary pigments, they are not as strong as permanent hair color, and therefore it can be hard to cover grey. For some people, it seems to work covering grey hair, but we can't leave any guarantee as this is very individual. Always try on a strand of your hair before applying the color to the whole hair to see the result.