Revlon ColorSilk Beautiful Color 41 Medium Brown 1 ea (Pack of 4) is an ammonia-free hair color delivers 100% gray coverage. Achieve rich, long lasting hair color and a radiant shine at home. It delivers natural looking, multi-tonal color from root to tip providing definition and boosting your hair’s dimension. It is also enriched with keratin and silk amino acid, Color Silk's ammonia-free formula leaves your hair in better condition. Instructions: Please follow the box instructions closely, but here are a few important points you might want to know right now about this hair color kit: For the best results, apply the hair color first to your roots in small sections (about 1/8" each). The typical leave-on time for allover color is 25 minutes, but if you have particularly stubborn grays, add 5 more minutes (so 30 minutes total). Using Ultra Blonde shades 03, 04, or 05? Add an additional 20 minutes to the usual time frame (so 45 minutes total on your head).