This is Crazy Color's brightest blue hair dye and it will certainly get hearts racing! This primary-color works perfectly as a mixer with other shades to achieve a creative tone of your choice. However, it also works well straight from the bottle for perfect bright blue hair. For optimal results, we recommend lightening your hair to level 9 or 10 (blonde) before use. It is also suitable for level 8 (light brown) hair, however, results will be tonal.