A hair color retouch kit, components of the kit, and methods of use and doing business. The kit can include one or more mixing containers. In one embodiment, a mixing container provides a colorant compartment for sealingly or separately containing a custom hair coloring formulation and peroxide compartment for sealingly or separately containing peroxide. The mixing container(s) can be used by a professional hair colorist to provide a hair coloring client with custom hair coloring formulation and peroxide that can be mixed and applied by or for the client to hair regrowth that occurs after a hair coloring session with the professional. The kit can provide other components as desired, such as a mixing spatula, an applicator brush, and instructions for example. The kit can be packaged in attractive and efficient packaging, include indicia identifying the source of the kit, and be customized to promote the colorist, salon, or other entity.
