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.
Highlight with a toothbrush. Several testers shared a smart trick for subtle results : Use a dye kit two shades lighter than your color and paint on highlights with a clean toothbrush or mascara wand. Place them sparingly where the sun would hit around the hairline and stemming from your part, Hill suggests. Start from the top : Since roots need the most color (and processing time), apply dye there first, then comb through the rest of hair to distribute it. Work in four to six sections, like pros do in the salon, to ensure full coverage.