Evidently there is no relationship between hair colour and attractiveness, since the only reason there are higher sales of lighter hair dyes is that there are more dark-haired people than light.
I have yet to hear an explanation as to why I dyed my hair black—twice!—and then a lighter shade of my natural blond in college, though. It probably had to do with just wanting a change. I can report, however, that my fuckability neither increased nor decreased—a decrease not being technically possible—after dying my hair or after my hair returning to its natural colour.
In a followup, Dienekes notes that hair dye sales are not evidence enough of hair colour preference.
