: You can change the main workspace (the Stage) from the default white to a dark gray or black. This is done by clicking an empty area of the stage and adjusting the Stage Color in the Properties panel.
your Stage is called the Pasteboard. By default, it is light gray. Edit > Preferences (Windows) or Flash > Preferences tab, look for the Preview Mode Highlight Color adobe flash cs6 dark mode
While the interface theme changes the panels and menus, it does not automatically change your "Stage" (canvas) color. If you want a dark working environment: : You can change the main workspace (the