By using a combination of two colors of highlights we get a smoother blend than if we used one solid color. Her highlights are with traditional lightener and 20 volume peroxide (and Olaplex), while her “lowlights” are actually still lighter than her natural color using a formula of 9N with 10 volume peroxide.

The result is that the overall color becomes lighter and brighter every time due to the lightener, but the lowlight color maintains depth and dimension throughout the ends while also preventing a solid bright line on the regrowth and giving a more blended effect as the color grows out.