This is really nice art, i am not certain whether this kind of art is really something which is often hosted on Danbooru but i have seen art in the same style that has been approved so i decided to try.

Other than that i have no idea of what to call the kind of upper clothing she is wearing so if anyone does than pleas add the relevant tags.

Edit: I also tagged the image with the "tentacle_hair + multicolored_hair + white_hair + blue_hair" as the implication of the "tentacle_hair" tag is that the alternative head tentacles are seen as "hair", that interpretation is correct right?