by the way, says that US'ns also use brunet as a sex-neutralish term.

Actually ®, Bingley, I've never seen this usage (brunet). And, to me, brunette, always connotes a woman. Also, having been in the theatre dealing with costumes and props, I've always seen wigs described on manufacturer's labels and storage boxes as brunette (or brown, auburn, etc.), never brunet.

I also find it interesting that we endeavor to draw a distinction between the masculine and feminine for brown/brunette, but that blonde and redhead are gender neutral.