Super quick tip on how to change the color of your background when using the Overlay option in InVision.
InVision will just take an average color from the corners of your document and set the background color to that.
So to fix, add a tiny dot (1px) to the corners of your design in the color you want.
Red dots? Red background!!
While you can add the background blanket in yourself if you like, this method allows for a bit more flexibility and more natural transitions between screens.
Note: My dots are a little bigger than they need to be for extra visibility.