We are using TIGI P.(pdot) and grey coverage is fab even on the lightes blonde shades and its one of the most true to shade colour ranges we have ever used. Also there technical support is second to non ,or at least it has been for us, and even more of a bonus for most colours the mixing ratio for tint to developer is 1:1.5 (or for extra coverage on the resistant greys 1:1 this never fails but don@t have to use it often) and the tubes are 65ml, so they go further, and are not an expensive range to use by any means. we have previously used koleston(wella) Igora Royal (schwarzkopf -and still use many of them as they are also very good) Viton s (clynol - got to be the worst) have used matrix but never been a fan - not the best on true to shade only in my opinion though. oh tried majirel too but not keen on condition results again only my opinion .