A system for preparing a hair-coloring composition comprising: a. a plurality of containers including first and second containers； b. a plurality of tablets disposed within each of the containers, each tablet comprising at least one of (i) permanent hair-coloring dye precursor and (ii) permanent hair-coloring dye coupler such that, a majority (e.g. at least a substantial majority) of the tablets in the first container comprise permanent hair-coloring dye precursor and are substantially free of permanent hair-coloring dye coupler, a majority of the tablets in the second container comprise permanent hair-coloring dye coupler and are substantially free of permanent hair-coloring dye precursor； c. a dispenser configured to dispense the tablets so as to provide multi-container tablet combinations comprising tablets from the first and second containers.Preferably, the dispenser is configured to dispense the multi-container combinations in accordance with at least one of (i) a hair coloring target and/or (ii) hair spectroscopy data.
