At the moment the Artboard background is a bright white and I work primarily in a dark interface. As such, every new document I open defaults back to a bright white artboard background. Is there a way to change the default background color and lock it in?
To make the artboard color choice persist look at the main menu up at the top then go to Edit -> Preferences -> Interface.
Inside the Interface section in preferences you will see 4 squares up at the top which change the overall color theme of Photoshop, just underneath that you find a select dropdown, it says "Standard Screen Mode:" before it. Choose the color you want for the artboard, hit OK. You may need to restart Photoshop for the change to take affect.