The boxed kits of hair colour available in supermarkets and chemist shops include disposable applicator bottles and all of the instructions necessary to mix hair colour at home. However, when buying hair colour and developer separately, handy instructions and containers aren't usually included. There are two different methods to mix hair colour at home using low cost items that are available at your local beauty shop.
Obtain a plastic applicator bottle from a beauty shop or salon. Make sure that it is large enough to hold both the hair colour and the developer, with enough air space left in the bottle to shake the mixture.
While wearing gloves, pour 30 ml (1 fl oz) of hair colour into the applicator bottle. Increase the amount of colour when working with long hair.
Add developer. The amount of developer necessary will depend on the desired results. For most hair colour, a one-to-one ratio is ideal, so add 30 ml (1 fl oz) of developer to the applicator bottle. However, when lightening your hair several shades, or going blonde, use a one-to-two ratio -- add 60 ml (2 fl oz) of developer to the applicator bottle.
Shake the applicator bottle until the mixture is uniform in colour.
Use the applicator bottle to apply the hair colour to your hair.
Use a non-metallic mixing bowl to mix the hair colour. Mixing hair colour in a metal bowl can cause a chemical reaction, so always use glass or plastic.
While wearing gloves, pour 30 ml (1 fl oz) of hair colour into the bowl.
Pour the appropriate amount of developer into the bowl.
Stir the hair colour mixture with a tint brush until it is uniform in colour.
Apply the hair colour to your hair with a tint brush.