Apple Shake 4 Tutorials - Manual (Page 151)

Tutorial 4 Working With Expressions 151
2 Display the alpha channel (press A with the pointer over the Viewer) and it will look
similar to this:
This area outside of the DOD is called the Background Color, and its color can be
controlled with Color–SetBGColor.
3 In Node View, select Over1.
4 Insert a SetBGColor node from the Color tab.
5 In the SetBGColor1 parameters, set the alpha value to 1.