Have you ever wondered?
2 neuroscientists attempted to explain why: http://content.time.com/time/health/article/0,8599,1654371,00.html
The study's summarised here: http://news.bbc.co.uk/2/hi/8200022.stm
And furthered explained here: http://people.howstuffworks.com/gender-color.htm
I myself have never liked pink. Back then as a little girl I liked yellow, then there was a period when most of my belongings were blue, and in different phases in life I've liked black, white, grey, brown, green, yellow, orange and red. Red, yes. But never purple. And never pink.
I may of course be an isolated case and shouldn't count. All I'm saying is that I have never liked pink and as far as I can remember, in VN the girls' sections in clothing and toy stores were not pink pink pink as in Norway and in some other European countries I've visited. That is why before asking why little girls like pink, one has to ask whether they do. What if parents, assuming pink's the colour for girls, buy lots of pink stuff for them? What if little girls merely choose clothes and toys with cute images which happen to be pink?
Starting from that, I suggest this experiment: there would be a mix-up of colours and images, then the clothes and toys would be divided into 2 groups. The 1st group includes planes, guns, cars, buildings, superheroes, ninjas, monsters... that are pink, and pink clothes with such pictures. The 2nd group consists of dolls, Disney princesses, doll houses, Japanese kawaii sculptures, models... that are blue, and blue clothes with such pictures. An experiment like this would indicate whether children go after the colours or not. At worst it may not work due to other factors, for instance, boys may have difficulty choosing between girly stuff and girly colour, that is, at young age they're still able to see pink is a girly colour according to parents and friends and other people around.
And yet in spite of such uncertainties it would still make more sense to me than the study mentioned above.
Also, I've found this very interesting article that refutes or at least questions several arguments of the neuroscientists: https://aethelreadtheunread.wordpress.com/2009/09/17/why-do-little-girls-like-pink/
There are some very good points.