Well, perhaps I'm not competent enough, but I suggest making the walls a little brighter. I guess light grey or smth like this will go. And as for me i don't like the mixture of brown and green.. but it's more about tastes, which differ as you know.

i hope this is of some help.

That's really nice one! I only think that colors are not quite pleasant. And there is a kind of mistake under the left chair (not supposed to be so much green i guess).