The thumbnails that appear in the Layers list of Motion can provide helpful information
about the items selected in that window. For items that are partially transparent (contain
an alpha channel), you can set the background that appears behind the image.
A pop-up menu with two options for thumbnail backgrounds:
• Checkerboard: Displays a checkerboard pattern where transparent pixels appear.
• Color: Displays a solid color where transparent pixels appear.
Background color well:
When Color is chosen from the Background pop-up menu, this
color well allows you to select a new background color from the Mac OS X Colors window
or the Motion pop-up color palette.