Ive used this colour on & off for the past 5yrs. Its the best i've tried yet! I always get people asking me how i get it so blue. The colour lasts longest when i bleach my hair till it looks almost white. If it's only blonde it looks mucky. I love the biro inky colour it has after i've just applied it. Then after the first wash it goes bright blue, people think it's electric blue. I recomend this colour to anyone who can bleach their hair well. My fav colour so far. -Sarah-