PhpStorm - Change theme for remote server view

In PhpStorm is there a way to theme remote connection files differently to local project files?

When open they are very similar looking to each other and sometimes it's easy to work on 1 view when I am meant to be working on the other!

Unfortunately you cannot change editor background or stuff like that to make it more visible in actual editor area.

But ... from what I see IDE already uses different background colour for the editor tab (the tab itself). It's not that visible there on your screenshot because you are using Darcula GUI theme where you do not see much contrast in colours used.

You can change that at Settings/Preferences | Appearance & Behavior | File Colors: choose more suitable for you colour for "Non-Project Files" scope (e.g. use bright red or blue -- whatever suits your theme and your preferences). Also double check that Use in Editor Tabs option is checked (should be already).

Please note that this will apply to any non-project files (i.e. even excluded or outside of the project root).

Another thing: in recent IDE versions (2018.2 is the latest stable ATM) the file edited remotely will have additional bar at the top of the editor with Compare / Revert | Upload and possibly other actions .. so it should be even more noticeable that you're editing remote file.