How can I make the editor view (where I put my lines of code) lightly transparent? It seems that it is overrided by the color schemes. And it is not possible to put transparency from color schemes because I have not the hand on the alpha property from the color pipe.
Is it only possible? I have tried through the UI and with the userChrome.css but without success until now.
Regards,
Unfortunately this is not possible. Being able to show whats behind an app window involves more than just the css opacity property. You could apply -moz-appearance: moz-win-glas to certain elements if you’re on windows but this won’t work on the editor itself.
Thanks for the answer! Will not be able to code and watch a movie on the same screen except with my “old shell”. 
Note I know Windows has a few apps that will let you add transparency to any window (as a whole), and you’ll likely have similar apps for Linux and OSX. Might be worth a shot if that’s what you’re looking for.