So now that you know it's successfully used on natural hair, what are the steps you can expect? Of the three-step system, No. 1 and No. 2 are done in-salon, as they're both chemical treatments. No. 1 repairs the disulfide bonds that are separated as a result of chemical treatments or heat styling, Olaplex ambassador Chad Kenyon says. No. 2 completes the colouring process, once the dye has been applied. The colour is rinsed, your hair is towel-dried and No. 2 is applied to the hair and left on for a minimum of 10 minutes.