The claim is that the greenish space makes dark objects appear more easily, and I know the “realism/fidelity” claims were clownishly wrong considering the space-fascist future features hand carts (that you have to buy with real world money!) and a star system loaded with 90s malls with hot dog stands, but something about making space itself a soupy greenish is… well… 
I mean they could also just make the ships, stations or whatever they think needs to be visible just look as if they had a light source on them, you know, like classic space games did.