Today I want to talk about Rin's hair. Rin's black hair goes down to her ankles, give or take a few centimeters. Her hair is black, but has a bluish tint. This, along with her inner hair being a rich purple, gives her a commanding look. The similarities between her and GSC President also can't be ignored- maybe she decided to wear her hair like her senpai while also being her own design, or maybe it's just a coincidence. What doesn't feel like a coincidence, though, is that GSC President's sky-blue and pink could be symbolic for sunrise, while Rin's black and blue may be symbolic for a starry night, with Rin being more on the nose than GSC President in this regard because of her tie and coat. It's a very good look for her, and could be expanded upon a lot.
Her Operator uniform has her put her hair into a ponytail, keeping her sleek and mobile in case she may need to run. Interestingly, she chose to tie her right bang up with a hairclip, but her left one is still free. This does mean that her earring is visible, but this begs the question as to why. Perhaps it's a subtle way of letting the others know who she is and what organization she stands for in case they somehow forget? Her ponytail also has more of a blue interior as opposed to the rich purple. While it might be a stretch, it's possible that this could have been done to represent that this was a desperate time, the darkest hour, so to say. And if you want to look at it another way, her earring being behind her ponytail could be an indirect nod to how this ends.
Asking Rin what hair product she uses, or trying to smell her hair, seems like it would end very poorly. But she seems like the type who'd have a subtle, powerful fragrance for her hair to try and command the room, a necessary thing for her to achieve with her position.