To darken blond highlights, color your hair with a mix of semi-permanent dye and a developer using the ratio recommended by the dye manufacturer. Brush your hair, and dampen it lightly with water before sectioning it. Apply the dye and developer mixture from root to tip, and let it sit. Wait for your highlights to darken to the desired level, and then rinse the dye out.
- Prepare the dye mixture
Carefully measure the correct amounts of demi-permanent dye and developer as stated in the instructions. This information is often written on the box. Mix the neutral or dark-colored dye with the developer in a dye mixing bowl.
- Prepare your hair
Brush your hair. Dampen it with water to facilitate the application of the dye. Be careful not to wet the hair too much.
- Section your hair
Divide your hair into manageable sections.
- Apply the dye and developer mixture
Use a brush to apply the mixture onto your hair in sections. Apply it evenly from the roots to the tips.
- Wait for the highlights to darken
Let the dye sit on your hair for a few minutes until the highlights darken to your desired color.
- Wash your hair
Rinse out the dye thoroughly. Use a deep conditioner to keep your hair soft.