Method and system for customized hair-coloring

A system for preparing a customized hair-coloring composition by dispensing material, the system comprising:

• a hair-treatment objective-prioritization user interface (HTOP UI) for receiving multi-objective relative-importance data describing a relative importance of different hair-treatment objectives for a potential hair-coloring treatment;
• a hair-state circuit configured to store a target color state for the potential hair-coloring treatment and initial hair-state data describing at least an initial color-state of the user's hair before being subjected to the potential hair-coloring treatment;
• and
• a hair-coloring-composition (HCC) prediction-engine responsive to input received via the HTOP UI, the hair-coloring-composition prediction-engine configured to compute, from the initial hair-state data and from the target color-state, a customized hair-coloring composition predicted to transform a color state of the user's hair from the initial color state to the target color state;
• wherein:
• the HTOP UI is configured so that the multi-objective relative-importance data describes a relative importance of (A) reaching the target color-state;
• and (B) achieving at least one auxiliary objective(s) or achieving a user-specified weighted combination of auxiliary objective(s);
• in response to receipt, via the HTOP UI, of multi-objective relative-importance data that prioritizes immediate-post-treatment color-state accuracy at the expense of achieving the auxiliary objective, the HCC prediction-engine computes a hair-coloring composition predicted to more accurately transform the user's hair to the target color state at the expense of achieving the auxiliary objective;
• and
• in response to receipt, via the HTOP UI, of multi-objective relative-importance data that prioritizes achieving the auxiliary objective at the expense of predicted immediate-post-treatment color-state accuracy, the HCC prediction-engine computes a hair-coloring composition that achieves the auxiliary objective at the expense of immediate-post-treatment color-state accuracy.