Generally speaking, yes, it certainly does seem that men prefer blonde-haired women. But, it is still up to an individual's taste. I wouldn't worry about what men like, I'd rather see what YOUR man likes. Perhaps he thinks you look great with auburn hair, not blonde. I know men who actually disapproved of their wives coloring their hair blonde.
In my opinion men do prefer women with blonde hair. I believe that men prefer blondes because of the society and that the blonde haired woman has been stereotyped as loose and ignorant. Much like lawyer are sharks and politicians are easily corrupted. The truth as I see it is that blondes have been given a bad rap and men with low IQ's are easily manipulated.