Generally, I use the color to specify the server usage (Production => red, Development => green, etc...)
But I could have Multiple connection to a production server.
Of course I can use other colors, but this means lot of color used!
Protocol could be added like a small mini icon displayed on the computer screen or on the side. I mean something like that:
- FTP: no change
- SFTP: shield icon
- AS3: amazon icon
Since icons are already very small, not sure if the render could be good...