Onyx Semi-Permanent Hair Colours Our darkest shade yet. Onyx’s high-shine, jet-black shade delivers flawless coverage and a sleek, mirror-like finish – perfect for those seeking maximum intensity in every strand. For the most vivid results, we recommend applying to pre-lightened hair. The colour on the pot is a simulation of the colour on a level 10. Our Rich Naturals range delivers even coverage and contains a deep-conditioning formula that nourishes hair from the first application.