I noticed a strange thing after doing a copy between 2 open sessions to two different servers.
They both had a separate tab with their own color.
In Session-Blue", I started the copy on a file with Shift-F5.
I then selected the other session, Session-Red, and copied.
After the copy, both color indicators of the open tabs had the color of the destination Session-Red!
This was corrected immediately by selecting the tab with the faulty color, but it is a bit confusing.
(The copy was achieved with "Duplicate via local temporary copy", but that is always the case with between-server copies)
It also happens the other way around. The remaining color is always the one from the destination session.
This was on WinSCP 1.5.3 standalone client on Win7 Prof. 64-bit