Renbow crazy color conditioning hair colour cream should be applied to bleached hair for a vibrant effect although it can be applied to normal hair the effects would be considerably weaker on medium to dark hair with better results on blonde shades most users of crazy colour apply to pre bleached hair crazy colour does not require the addition of peroxide after shampooing towel dry the hair and apply spreading evenly over the hair leave for 1015 minutes then rinse thoroughly the h