OK, I'll do one with this green room here--and like I'm just a person on the internet so you can feel free to ignore all of this, it's just how I would go about it.

So like I'm just going over your final file so I'm gonna be a little messy, but I decided to bring interest to the front with the brighter and warmer green tone, and let it gradate back into a cooler gray like you had originally. And, I did it to the bar as well so you'd get a sense that the bar is close to us, but not as close as the floor. The bottles were nicely drawn, and I liked their colors (in fact their colors became the floor color) but they had a lot of detail and contrast because it's the darkest and the most saturated colors together--so I toned it way down so the focus wouldn't stop at the bottles, since I assumed this was part of a larger image and you'd want your people to be the focal point. (and some highlights on a a bunch of the bottles would be fun, since they're made of glass, but I didn't do that) And TBH I could probably make that whole bottle section a little lighter as it fades into the back, but that's just an afterthought and I'm not entirely sure what the angle of the bottles should be in regards to the counter.
Also, the light comes from above--not sure which direction it's coming from, and so I plopped some shadows on the chairs, and added some lighting to the top of the chairs. The chair closest to us, with the brightest lighting. The corner walls and the ceiling should also be different colors where they meet--so I made the ceiling dark, and the back wall slightly lighter than the side to give more of an illusion that they're meeting at a corner.
Anyway this was just something done really fast, but hopefully made it make sense?
And like I don't know what the vibe of the original painting was, so maybe green was the wrong color but you can do the same with different shades of gray if you want to keep it more gray.
But one of the big things I noticed going through these is I really don't know where your source of light was, so I didn't do much shadows. So that might help if there was more clarity in the lighting for your future backgrounds.