Japanese do mix emoji with kanji and kana. Are emoji any less graphemes than the mor pictographic han characters? I don't think the colors are normative though, any more than the exact shape is. A different representation of a love hotel ought to be fine.
The colors I'm referring to are the ones in the names of the code points, such as the ones the Germans complained about It doesn't get much more normative than that.
Ah, that grapheme doesn't actually have color IIRC, but the hair is not filled, thus giving the impression of a fair-haired person (rather than dark haired)
