Its a semi permanent dye that is intermixable and basically the same kinda thing as directions or crazy colour except its way more pigmented and so the neat colours are very dark. This means you have full control over the depth of the colour in a way, if you want to make lighter shades or pastels you can dilute a colour with clear or conditioner.
Ive used them before, mostly on myself as the only way you can get them in the UK is buying off ebay through a seller in poland, which obvs isnt ideal for insurances purposes. Recently however, people have been complaining about the colours being a bit dodgey in having different consistencies or pigment concentrations. Stuff like the yellows either looking super bright and golden or more greenish.
Joico intensities is another make that guy tang uses, they have good reviews also. For a larger shade range with less intermixing use directions, uk based company that also make good colours.
