You must condition when you're done. "If you skip the conditioner step, it leaves the cuticle open and the color keeps working," says Ionato. "So don't be surprised if you end up with much darker hair than you wanted." Don't throw away the conditioner in the kit, and if you do, make sure to use a deep conditioner in the shower after you rinse out the dye.
Don't trust the model on the box. Sure, the woman smiling on the front of the box looks beautiful, but the color of her hair is a fantasy. "The color always ends up lighter than the model's hair on the packaging," says colorist Dana Ionato of the Sally Hershberger Downtown salon in New York City. "The developer in at_home permanent dyes is very strong stronger that the ones we use in the salon so it lifts the color and makes it lighter than what you see on the box." A better estimate on how the color will end up is the chart on the top of the box, which shows you the final color you get from a range of different hair_color shades.