Wishlist
When using Rich one can set "default on default" as a means to preserve the native terminal color presence. It would useful, especially for inline mode, to have a TCSS styling mechanism that maintains the same Rich default coloring behavior.
Possible Solution
A possible scenario that is somewhat semantically consistent might be to add as valid a 'none' value to both color and background styles.
Example
Widget_name {
color: none;
background: none;
}