Changing the settings of one of your sources or palettes is done in the sidebar. The sidebar will open to the "source selection" pane, where you can add a live source, a ScopeLink source, or a movie file. The icons at the top of the sidebar allow you to toggle between palette settings, source settings, still images, and predefined targets. Clicking the gear icon in the upper right corner of any palette allows you to adjust settings for that palette.