The present disclosure relates to a hair dyeing process comprising dyeing the hair by applying to the hair at least one dyeing composition comprising at least one dye precursor; rinsing the hair; and post-treating the hair by applying to the hair at least one aqueous composition comprising at least 30% of water and at least 20% of at least one organic silicon compound chosen from the silanes that comprise one silicon atom and the siloxanes that comprise two or three silicon atoms, wherein the least one organic silicon compound also comprises at least one basic chemical functional group and at least one hydroxyl group or hydrolysable group per molecule.