I think the coloration is good, but I would have defaulted a bit differently in the permissions. I would have made all user bits green, all group bits orange, and all other bits red. Not only does this denote the possible security implications of the permissions, but it also maps well to what I'm usually looking for - what are my permissions, and being able to see all those quickly with green would be useful. As an added benefit, there wouldn't be as many per-character color changes in that section, so it would be less busy.

Awesome work, BTW. I love seeing interesting re-imaginings of old standby utils. I was actually thinking of doing my first real Rust project as a cat replacement. I was thinking of calling it calico. ;)