I've used this kit to strip or add streaks to my hair for years. I use the refill kit, as I use foil to add it to my hair. If I use it to go blonde or have blonde highlights, I add gentian violet to my conditioner to get the brassiness out. I also treat blonde coloured hair with Hask's Blue Camomile Deep Conditioner every other week.
This is definitely a home kit, so you won't get those ideal tones you would at the salon. If you are not prepared to tone and take care of your hair afterwards, this is rather not for you.