Hair goes gray as the follicles' supply of color-producing melanin becomes depleted with age. For most people, gray hairs start to appear in their 30s, but the onset and degree of graying has a lot to do with genetics. In some cases, graying is temporary, with pigmented hair growth resuming after treatment of illness or injury that led to the graying. When dying gray hair, you should change to a lighter color that will easily blend or mask gray or white regrowth. Often, this lightening of the hair requires prebleaching, especially if you are transitioning from naturally dark hair or going blond. Prebleaching softens the cuticle and opens it up so hair dye can penetrate the shaft and last longer.
Prepare bleach mixture in a bowl. Follow the directions for mixing ratios on the powder and developer (ammonium-based hydrogen peroxide) product packaging. Wear gloves and use the opposite end of the brush applicator to mix it into a paste consistency.
Section the hair into four or more parts, depending on the thickness of hair. If you have a lot of hair, separate it into more sections so the mixture can be evenly applied throughout.
Quickly and carefully work your way upward and toward the hairline from the back of your head. Apply lightening paste to the darkest sections of hair first using the applicator brush. This will allow the bleach more time to remove the pigment.
Cover the entire head in the plastic cap to retain heat for processing. This will take several minutes, depending on the formula you use. Check the product instructions for the proper time frames according to desired results.
Rinse hair and wash with a toning shampoo. These formulas usually have a purple tint that helps to neutralize brassiness (orange or yellow tones) left in the hair. Follow with a quality deep-conditioning treatment to restore hair's moisture.
Make sure hair is in strong, healthy condition before bleaching. Hair products appropriate for gray hair treatment often have blue or purple hues. If dying hair after bleaching, make sure the color formula is appropriate for gray hair. Gray hair tends to be more coarse and color-resistant. If several applications of bleach are required to significantly lighten hair, applications should be spread out over several days to allow the hair time to recover from the consecutive harsh treatments. Use a color remover if your hair is dyed before bleaching.
Bleaching hair is damaging chemical process that may change the texture of your hair, making it brittle and weak. Do not bleach hair if it is already damaged, weak or over-processed. Do not apply bleach directly to dyed hair. Bleach will eat through dye but cause major damage to hair in the process. Follow instructions closely and carefully when dealing with bleaching agents. Adhere to quantities and time frames to prevent burning hair and scalp. Keep bleach away from eyes and do not use it on eyebrows. Do not store afterwards.