Okay, I'm sure there's a perfectly logical in-story reason for why each of the four Green Lanterns above gets what colored ring, and I'm sure race had nothing to do with it, but man, Indigo Lantern John Stewart's get-up is certainly grotesque compared to his fellow Lanterns' new costumes.Purple on purple glowing camo? Uggh. I can barely stand to look at him.
The others look like they basically have costumes that blend their regular Green Lantern costumes with those of the other Lantern Corps, but instead of putting Stewart in a purple version of his costume or an Indigo Tribe costume (which, as generic space native clothing, perhaps might have been decided against to avoid the appearance of a racist or at least stereotypical choice of who wears what), they put him in a costume that recalls his retconned career as a Marine sniper (Of course, Hal Jordan's not wearing a yellow bomber jacket, Guy's not wearing a red football uniform and Kyle's not wearing a blue Nine Inch Nails t shirt).
I'm not a fan of the Stewart-as-Marine portrayal, although I understand it's in keeping with the version of the character that appeared on the Justice League cartoon and is now the predominant one. I guess I've just read too many Batman comics over the years, but guns reveal a lack of imagination to me (plus, they're a coward's weapon, as Batman always says), particularly when they're ring-generated guns made out of space-alien wish-power capable of creating anything at all. Giving artists a reason to give him that costume seen above is another strike against it.
Anyway—John Stewart, what are you wearing, man? I think you might even look better in Carol Ferris' Star Sapphire costume than all-purple camo.