Patent ID: 8336582

Claim:
A method for preparing a hair dye mixture, the method using a scale and control system in communication with each other, the control system including a memory and a display, the memory containing a formula defining instructions for blending a hair dye mixture using one or more colorants and/or dye blending materials and amounts recommended for producing a pre-defined batch size of the hair dye mixture, wherein the instructions are displayed on said display, the method comprising: displaying the instructions for producing the hair dye mixture on the display; and monitoring a weight on the scale as colorant(s) and/or dye blending material(s) are added to a receptacle on the scale in accordance with said instructions while using only hair color manufacturers' standardized packaging; recalculating the formula of the hair dye mixture for an adjusted batch size when a weight of a colorant or dye blending material being added to the scale is different than the amount recommended in the formula for the pre-defined batch size; and displaying the recalculated formula on the display for the adjusted batch size, thereby preventing excess hair dye mixture from being produced and spoiling due to oxidation.