Intense caring color: your hair is healthy looking and strong in combination with the pre-color serum. Even color from root to tip: The protective pre-color serum conditions the hair before coloring for a more even color result from root to tip. Up to 80% less hair breakage: enhanced kbond-plex repairs inner hair structure and coats the hair surface after the coloration process for strong and healthy looking hair. 100% gray coverage: gray coverage with long lasting color fidelity giving you fuller hair with up to 80% less hair breakage (vs. Untreated hair). If your hair is longer than shoulder length, we recommend using 2 boxes of keratin Color Hair dye for the application.