I tried out all the vivids - purple, blue, rose red and turquoise. OMG. So pretty and so fun. They work really well when highlighting smaller piecey sections. Also, I found that really using your fingers to blend the colors into the hair makes it look and feel natural.
I love them all. I gave them to my 11 year old, and she has done her hair everyday with them. And everyone else's hair. It goes on thick, but if brushed in lightly instantly becomes a tie-dye fade and flexes with hair's natural shape. It comes off easy too, washed out of a toddlers hair with baby soap and left only a smudge on her scalp, probably would have come off if I tried harder. Light, pleasant scent too.