The question was "what hair-color men felt was the sexiest on women"...NOT "Do/men judge women by their hair color."
Meeting someone face-to-face, you <b>are</b> going to react to their looks first. It might be their smile, clothes, height, any one of a number of things, but appearance DOES have a factor.
Now, back to the question/poll. From what I've seen, this factor may change...in fact, I think it almost certainly will, given enough time. Let me explain before I get hit with a bunch of messages. When a guy (in this case) is dreaming of his ideal partner. Let's say he imagines a lady a typical 5'4" (average curves) with medium-olive skin and brown, wavy shoulder-length hair. At the next office party, he meets a woman 5'8" high but very-thin, with streaked blonde hair and freckled skin...they find much in common and soon his fantasies change to reflect his new attraction.
In short ... I'm not gonna get too worried about what hair color turns out 'best' here.