Highly Damaged hair loses color easily as it doesn’t have enough substances which graves onto the color properly.
A Cut Above recommends Herb Color as toner.
Herb Color was originally formulated as an all-natural ingredients hair treatment. Later diamine, a chemical pigment used in all colorings, was added to the treatment to improve hair condition without damaging it. This is the reason why the color lasts longer.
Additionally, the color lasts after applying Keratin-Blow-out for the same reasons.