Moodswings makes it easy to change your development configs from the terminal.
gem install moodswings
Create folder in ~/.moodswings
Create new file .mood (see examples below)
desktop_background "~/Pictures/Wallpapers/really-dark-pic.jpg" open_app "MenuBarFilter"
There are only helper methods for OSX right now, and they use osascript to execute commands. Feel free to create more helper methods for different platforms, or improve on the ones currently existing.