Changing Viewer background color

1) Select the Project in the Layers list

2) Click "Inspector"

3) Select "Properties"

4) Change the Background Color:

EDIT: note that the Background is actually transparent (see the bottom line in the image), so the yellow color in the above example is only for visualization inside Motion, it will not be part of the project if exported or used as a template in FCP.

Changing the background color works great and can make working some projects a lot easier to deal with.

There are also other methods:

At the top right of the canvas are several drop down menus — the one highlighted is a "Canvas View" menu

These are the keyboard shortcuts:

[There is also access to these in the View menu > Channels option.]

The Transparent option changes the canvas to a checkerboard as shown:

Alpha Overlay will change the canvas red.

So you can switch back and forth from these options to the Background you have set up in the Project Settings.

The rest of the options lets you inspect the color components and alpha of your scene and Exposure Out of Gamut... I'll leave these up to you to figure out.

Thank you, Fox. As usual, you provide the best solution!