fallback

Fallback for this association kind. This is used when no color scheme is associated with this kind. For example, .TabBorder specifies that its fallback is .Border. When the tabs are painted, it will try to use the color scheme associated with .TabBorder. If none was registered, it will fall back to use the color scheme associated with .Border, and if that is not registered as well, will use the color scheme associated with .Fill.