See documentation for details.

select "options" in the menubar and expand the menu at "color ->". The selected color is attach the the current session. If you change the session the background color will change to default or a color already selected the the session.

It would be nice to have the ability to change the color of the background and/or titlebar. I have to manage a bunch of different websites which requires me to have multiple WinSCP windows open. It would be nice if I could color code each one to my taste to easially differentiate between each session.

Other than that, great program :)