To bleach hair, mix bleach and developer, and apply the solution to sectioned hair using a hair brush or hair color applicator. Read the hair-coloring product directions carefully, and follow the instructions to the letter.
Coloring bleached hair often produces the best results and is a common practice according to Clairol. Bleached hair removes the pigment from the hair, leaving the hair ready to fully absorb a new color.
To color bleached hair, treat hair with a prewash and conditioning treatment, apply a filler color, then apply the desired hair color. Condition weekly with a deep-conditioning treatment.
When hair is bleached, it goes through an oxidation process that dissolves the color pigments in the hair. According to Hollistics, during oxidation, bleach ingredients release oxygen molecules that bind to the hair's melanin pigment, eventually dissolving the pigment.
Bleaching hair is very damaging. Though it may lighten the hair by removing the color through a chemical reaction with melanin, the result is an open hair shaft. The moisture and oils provided by the scalp are stripped from the shaft, according to Anne Marie Helmenstine...
The most effective way to cover bleached hair is to dye it. Dyeing the hair dark will easily cover the bleach.
To bleach your hair at home, put on protective clothing, mix the bleach, and apply it to the center of each strand. Apply the bleach to the roots, pull it through to the ends, and process until the hair is light enough. Rinse completely, and deep condition the hair.