The entire alignment of Allos' face from her forehead to her chin
The shadow on the clothing of Suzuko, Kiyoi and Ruuko makes no sense.>>2500476
I've had to rewrite this several times so I hope it makes sense.
To put as basically as I can, Ruuko's palette isn't aesthetically pleasing. In Suzuko's and Kiyoi's palette there is contrast that creates an aesthetically pleasing composition of colour. Ruuko's uniform is too dull.
If I break each palette down into three main colours in RGB colour space, it looks like this
Suzoko: Green - R 108, G 119, B 89 Red - R 216, G 108, B 108 Grey - R 73 G 73 B 73
Kiyoi: Blue - R 88, G 93, B 125 Red - R 202, G 85, B 104 White - R 255, G 255, B 255
Ruuko: Red - R 188, G 83, B 89 Blue - R 87, G 88, B 109 Brown - R 77, G 66, B 72
There simply isn't enough range between colour channels to create a desirable colour contrast.