What kind of hair do you have? If your hairs thicker and courser I would do the 30 if your hair is a little thinner a little weaker I’d use 20. Also f you can try to get your hands on sebastian cellophane in the color redred or redissimo you can add that in your dye when you color your hair and it will help with color and shine. Also use a sulfate free shampoo I recomend te l’oreal sulfate free shampoo for color and add the cellophane color in your shampoo as well (it will make it red) so everytime you wash your hair it revives it. I only do my hair once a month. It does stain tho make sure you use it in the shower.