Parent: $root.$constants
| kBGThemeContainer | Standard generic container background |
| kBGThemeControl | Standard generic control background |
| kBGThemeMenu | Standard menu background |
| kBGThemeMenubar | Standard menubar background |
| kBGThemeNone | No background theme |
| kBGThemeParent | Use theme of parent container |
| kBGThemeTabPane | Standard tab pane background |
| kBGThemeTabStrip | Standard tab strip background |
| kBGThemeWindow | Standard window background |