I'm not a fan of all the white, and I'd like the standard background color of the windows (nemo for example) to be black instead. Is there some way I can manage to do that? I've been looking at dconf-editor and the values for gtk-color-scheme, but they only ever change some windows (pidgin for example) but others, like nemo just stay white.
i would like to know this as well. cinnamon themes only change the task bar and menu (and a few other things) but the main windows (nemo) are not changed at all, how do we change the background color of those windows?
Your best bet is to find another gtk theme that better suits your personal taste. That is what actually controls the look of your applications. Check places like gnome-look.org and deviantart to find hundreds of different ones. They usually come as a compressed file when you download them. Simply extract the file and copy the themes folder to either ~/.themes (makes it available to only that user account) or /usr/share/themes (makes it available to all user accounts) and then set it as your window controls theme.