Kaleidoscope Hair: As was mentioned back under You Gotta Have Blue Hair, there is a certain shampoo which is specifically designed, via hair-clinging nanites, to let your turn your hair into an active LCD display surface. (For a week or two until it starts wearing off, although you may get a few dead pixels before then.) Or, for those with more permanent ideas, the implanted-nanogene version of the above that you don’t need to renew. These allow you to have very impressive Kaleidoscope Hair indeed – heck, you can even run fractal screensavers or actual video clips on it if you like.
And if you’re just looking for a reliable way to create this effect, regardless of what wind or in-flight airstream or other sources of disarrangement might do…
(I would thank Hasbro for letting me borrow Rainbow Dash to illustrate my point, but honestly, I’m just counting on them not caring that much.)
…then you can have it.
You Gotta Have Blue Hair: Not all the uses of genetic engineering – or other technologies, including that shampoo that turns regular hair into a fully-functional LCD display surface for a week or two – are for even vaguely utilitarian purposes. Enough said.
(As a side note, the silvertouched – see Our Dwarves Are All The Same – do this naturally with some metallic colors, due to their symbiotic silverlife accumulating metal within their bodies, which turns into metallic strands in among their hair, among other things.)
Letting Her Hair Down: This trope is essentially enshrined into standard eldrae etiquette, (especially for women, although long hair is de rigeur for both sexes); whether one wears one’s hair up or down is universally understood as a signifier of whether one is busy working (and therefore should not be disturbed), or available for socializing en passant.