Today I want to talk about Aoi and her hair. Aoi has neck-length hair that, in simple terms, is blue-purple, but seems to be close to 7070cc (listed by Wikipedia as Celestial Blue, based on a Crayola crayon color that hasn't existed for over 100 years, which is why the hex itself was given). Aoi is unique in that, to my knowledge, she has the hardest hair color to definitively label because of how close the color is between purple and blue. This does, however, suit the general nature of the GSC, especially in how their color scheme seems to represent space in one way or another, with Aoi's hair color feeling like the twilight between the sky-blue of day and the black of night. Her eyes being a very pale blue to the point of almost looking like she has the moon itself in her eyes, as well as most her outfit being bright in general, causes this enigmatic shade of hair to stick out more. Perhaps I'm simply getting distracted trying to solve that which has no answer.
Her hair style looks to be a long-hair pixie cut favoring her right side. It's a subdued, yet practical, style, with her bangs at just the right length to warrant a haircut sometime soon. Her hair is somewhat ruffled, which is a bit surprising, given Aoi's meticulousness. However, this could be because she's a hard enough worker that it just ends up like this, or it could be due to stress. If it's the latter, then she is incredibly good at hiding it.
Her eyes look like a cat's, with the aforementioned moon-like white coloring. It's weird how Aoi's a simple design, yet the colors are anything but, to the point of mesmerizing somewhat. She has a beauty mark just below her left eye, and her visible pointed ear has two small black earrings on it. Aside from that (and the gloves being tugged on), she's a relatively mundane design, with impossibly complex colors.
Before, I posited that perhaps the GSC members could represent the Seven Sins or Virtues, in a Tarot-card like form where it depends on perception. Aoi feels like she would represent Temperance, in that case, but perhaps even Chastity. Maybe looks are deceiving and there's an ulterior motive to re-balance the books so often (Lust), but she seems incredibly restrained, even if that were the truth of the matter.
The halos of the GSC members always give the impression of astronomical events. There's two that come to mind, the first of which being a solar eclipse, in how her halo has two circles, with the inner one potentially obscuring the outer one somewhat, with the center star-like shape being the changed perception when this phenomenon occurs. Haine's halo could also represent that, but Haine's halo may represent other things as well, much like Aoi's. Another interpretation could be that her halo in the representation of a nova, or supernova, where the center of the halo represents the progenitor body, collapsed into a neutron star, with the inner circles representing the expelled solar masses and the outermost ring being the extent that such an observation will be seen. In the case of a supernova specifically, then the innermost ring and star could represent a black hole instead, with the middle ring representing the event horizon, and the outermost being where its gravitational pull begins. One final interpretation of her halo could be the concept of a binary star system, with the two outermost pillars representing the stars, and the interior rings and star being the gravitational pull the two experience. There are definitely many other ways to interpret Aoi's halo, her eyes, her hair, or Aoi as a whole. If this were a work of horror and Aoi were the antagonist, then many a writer would call her eldritch, in how she may be seen and perceived, yet to put an accurate description on it is a difficult task.
While the above is true in that it is hard to describe Aoi, and as a natural conclusion, her hair's scent is also hard to describe, the scent to her hair is somewhat of a citrus, meant to provide a laser-like focus to important tasks at hand.