In PL/SQL Developer, the user can set different background colours in the code editor for different connections. Is this something that can be set in Plyxon (I can't seem to find such an option)? If not, can it be added to the list of enhancement requests? I find it useful to have different background colours for different connections so I can tell from the colour if I'm in a development, test of live environment.

This is currently not possible, but I have added this to the list of enhancement requests.

I would like to see this feature as well.
I think us long time "PL/SQL Developer" users are pretty much going to expect Plyxon to contain all the features we've gotten used to over the years and there are a lot of them.
Either that or PL/SQL Developer needs to be rewritten the same way Plyxon is, i.e. faster and more modern.

The PL/SQL Developer feature set is of course enormous. Plyxon will need a little time to get there.