Cover up highlights by dying hair a darker color with home hair coloring kits. Choose a permanent hair color that matches the hair's darkest shade.
Wait at least three weeks before coloring over highlights to avoid damaging hair.
Step 1: Choose a hair color
When covering highlights, it is better to go darker rather than lighter to ensure that the highlights are covered completely. Another option is to choose a shade that matches the highlights if a lighter color is desired. Choose permanent hair coloring, since semi-permanent color fades too quickly to cover highlights.
Step 2: Prepare to color the hair
Wear old clothes and keep anything out of the area that might become damaged by hair dye. Wear gloves and prepare the hair color according to the package directions.
Step 3: Start coloring hair
Section off the hair into smaller segments. Clip hair out of the way until that section is ready to be colored. Work the color into the hair from root to tip, saturating it completely.
Step 4: Time the coloring process
Set a timer for the exact amount of time specified on the hair coloring package.
Step 5: Wash and condition hair
When the timer goes off, rinse the hair dye out of the hair and condition it. Many hair coloring kits come with a specially formulated deep conditioner for use right after coloring.