I love the colours (gray), especially when neon colours are added to the mix, they really pop! For how much I love the show.... I hate the "main cast"once you watch it through you'll get it. Fudge I hate them all! "Main cast" compromising of Akashi, Sasame, Minashi, and Tugumi, kind of a slight spoiler... But! Emiru and Mahmu's friendship was one of the saving graces, I cried so much for those two. For a dystopian anime, where the threat is clear but the solution isn't, it's honestly worth a watch if you can get your hands on it.
Also as much as I love Emiru and Mahmu my OTP for this anime is hands down Raika and Iwato. The progression of the relationship is cute, and is a complete polar opposite of Akashi's relationships with all the girls that throw themselves at him.
So in conclusion if you want a mech, psychological, sci-fi kind of show where people die... then this is the show for you!