well i been colouring my hair for my self for a bout 2 years now and it comes out pretty ok...after i apply the colour i always put on a shower cap and go under a dryer for a while...it supposedly helps the colour take to your hair faster...also if on de box it says leave in for 30 minutes i leave it for about 45minutes...lol...not sure if dat safe...lol..but my hair thick no rass...