Semi-permanent and demi-permanent hair colors allow for perming and coloring hair on the same day according to Clairol. When doubling up on these hair treatments, the perm should always come first, followed by the color.
The chemicals in a perm cause the hair shafts to open. This leaves the hair porous, and porous hair is perfect for the coloring process. The hair color takes less time to absorb, and less time on the hair means less damage to the hair.
Make sure to only use semi-permanent or demi-permanent hair colors after a perm. If a harsher permanent hair color is needed, wait at least a week before dyeing to avoid damaging the hair. Maintain the vibrancy of the color by using shampoos and other hair products specially formulated for chemically and color treated hair.