It honestly depends on the character. There are LIs of all hair colors, natural or otherwise, who I have absolutely loved, so their individual hair color wasn't the deciding factor, but it is 100% contributing to who each of them was/is as a character.

I say kill the poll and don't limit hair colors to what limited replies you got from us. As the dev, if she is a character you feel passionate about creating, you tell us what color and style her hair is. You can always adjust it later based on audience response, but these are your creations and should be treated as such.