she's allowed to tell you what to wear, how to get your hair cut, what nights you can go out with the lads, etc., because she's a girl and you men love being bossed around!
whereas you, as a bloke, are only allowed to say positive things about her, and under no circumstances make any derogatory comments about her hair, clothes, shoes, weight, whatever.
that's just the way life is and the sooner you understand that, the nicer life you'll have :o)
seriously, don't tell her you don't like it as there's nothing she can do about it now and she may not like it herself, in which case you'll only make things worse. and if she does like it, which she probably does, then you're just going to have to get used to it.