The “girls preferring pink” thing is not set in stone, and in fact there are good reasons to suspect it is culturally determined.
And then he gives examples. But if I may add another remark to his rant: it turns out that the categories of blue and pink are also culturally determined. Actually, the colour blue didn't even exist as a separate entity before the Middle Ages. Ancient Greek, for example, does not have a word for blue, and Homer speaks about the wine-coloured sea.
I think that the study of colours and their perception is more a subject for historians than for biologists or physicists. On this subject, one of the best books I've read is Blue, the History of a Color, by Michel Pastoureau, in which the last chapter briefly talks about the very recent (and very occidental) association of blue and pink to boys and girls, respectively.