Color Perfect Permanent Haircolor has an excellent array of creme gel colors formulated to be completely intermixable to create any shade desired with predictable natural-looking results. Determine desired amount of working product. Mixture ratio is 1 part Color Perfect hair color to 2 parts Liquid or Creme Developer. Pour appropriate developer into a plastic applicator bottle or bowl. Add desired Color Perfect hair color. Mix well. Development time: 30 minutes. For resistant hair or when using high-lift blondes: development times may be up to 45 minutes.