Colouring bleached hair to a natural brown can be tricky and requires patience. Applying a box of brown colour without properly preparing the hair can turn bleached locks to an ash green, grey or other undesired shades. Most salons consider this task a "corrective colour" service and usually charge by the hour. Though best left to the experts, doing the colour at home is not impossible and can save a significant amount of money.
Determine what colour is needed to pre-pigment the hair. Inside each hair strand is a red, orange or yellow "base" colour that appears when the natural colour is stripped. Base colour, known as "filler" must be applied first to prevent a green or ashy final result.
Choose a red filler if the desired result is dark brown. For medium-brown results, use red-orange; light brown results will need orange. Colourful Professional Protein Filler, sold at supply shops such as Sally Beauty, fills the hair with base colour and adds protein to porous ends.
Follow package directions and apply filler. Depending on the manufacturer, the fillers are processed for various times. Some require rinsing, others require only towel blotting prior to final colour application. Don't panic when you see a bright red or orange result, this is normal.
Towel dry hair and apply brown colour according to package directions. Permanent hair colours and demi-permanent hair colours require the product to be mixed with a developer. Depending on brand, semi-permanent colours might not require a developer and last between 6 to 12 shampoos. Demi-permanent colours last up to two months but are more gentle on the hair than permanent colours.
Rinse, shampoo, condition and towel dry hair. Use a leave on conditioner for added protection against split ends. Bleached hair that has been colour treated is extremely vulnerable to breakage.
Repeat process if needed, waiting at least one to two weeks in between colourings. If the colour is not even, or fades quickly after shampooing, a second application may be necessary.
Using a demi-permanent brown colour will outlast a semi-permanent colour, producing the best possible results with the least amount of damage. For even colour results, take small sections to ensure product covers every strand. Use a shampoo for colour treated hair for longer-lasting results.
Wear gloves for both the filler and colour applications, as both stain hands.