You could also advise a temporary colour like Perfecton (0/56) or (0/4) which you dilute with water and spray in dry hair and then blowdry it in, that way you can control the ammount of colour that you deposit. It is temporary though and does rinse out almost completely on the first shampoo but is loads of fun as you can change it or make it brighter the next time, otherwise you could also try the directions/ crazy colour/ Adore route. We also use the temporary colours on dip-dye in the salon to add something different.
I have pink hair but have found it quite difficult to get the baby pink straight away. Normally it takes a few shampoos before the colour is quite right. I use Carnation Pink in Directions, and basically 1 jar of Carnation Pink to 1 jar of water mixed together and applied with a tint bowl and brush and left for only about five minutes and then rinsed completely out. And then a light shampoo if it is too bright...