Color variables in modes set to nothing/blank/null/empty

We need the ability for variables in modes to have a nothing, blank, null, or empty value.

For example, filled vs ghost buttons. In filled I have a fill color but in the ghost button it needs to be clear—so either alpha 0 (it works but it’s not elegant) or nothing (also not supported) for the variable mode to work properly.

Otherwise I can’t use variables for changing themes on objects like these.