To make a change to all your sessions, head over to File – Options – Types – Terminal – Colors and check Override terminal colors You can also Import and Export, from this window, to share the settings.
It is also possible to change the color of the highlighted text and background. These options are located at the bottom of the Terminal Colors page.
With the dropdown it is possible to select how the terminal text is highlighted. Here are some examples of the Selection type:
To change the color of a specific session, go in your connection's Properties – Terminal – Display.