Methods for creating custom hair formulations include generating a first input set and a second input set, formulating a hair formulation recipe, displaying a predicted hair color on the user input device, and dispensing a hair formulation from a dispenser. The first input set is based upon a plurality of present hair state inputs received by a user input device of a hair formulation system. The second input set is based upon a target hair state input received by the user input device. Formulating the hair formulation recipe includes using a processor of the hair formulation system that is operatively connected to the user input device to formulate the hair formulation recipe based upon the first and the second input sets. The predicted hair color is based upon at least one present hair state inputs and the target hair state input.