The process for mixing hair dye and developer typically requires a 1:1, 1:1.5 or 1:2 ratio of dye to developer. The specific mixture depends on the product.
Hair dye requires multiple steps, including the application of a mixture that includes the dye and a product that allows the dye to color the hair, which is known as the developer. Different products require different ratios. Once the ratios are determined, the developer is usually added to the applicator bottle or a nonmetallic bowl. After the color is added and mixed in the bottle or bowl, it should be applied to the hair according to manufacturer directions for the proper time.