Inactive window identification

Currently, there is no visual difference between an active and an inactive window for the desktop app. It has happened to me more than once that I think I alt-tabbed away and started typing, but really I'm typing into the wrong box on the wrong window. It's specially annoying with multiple monitors. I know windows isn't doing a particularly good job at differentiating them either ever since windows XP, where the difference was unmissable. I'm not asking to go that extreme, but anything is better than absolutely no indication.