stain [stained, staining, stains](to treat a microscope specimen with a dye) verb [UK: steɪn] [US: ˈsteɪn]
decolorareverb
bleach [bleached, bleaching, bleaches](to treat with bleach) verb [UK: bliːtʃ] [US: ˈbliːtʃ]He bleached his hair yesterday. = Si è decolorato i capelli ieri.