Wonderful dye with incredible shiny result. One of my favorite series from Wella, it can't even be compared to the Perfect+Me series, which is more popular in terms of results.
I use the 10/81 on natural hair level 7 (dark blonde sandy) with 30 or 40 volume developer for about 40 minutes and I have full coverage of the roots and it lightens my hair to a level 9 without bleach easily and with less damage to the hair. The shade comes out as a beautiful pearl blonde with sandy undertones that I love (clearly not exactly like the indicative photo on the color chart since I don't lighten my hair before dyeing it).
I have tried many dyes from Wella as well as other brands and none achieve this shiny result like the illumina series. I highly recommend it and wouldn't change it for anything!