Tab Coloring By Filter (Regex)

I assume I’m missing something pretty obvious but have had a search and can’t find anything, how exactly am I supposed to use the “Filter (Regex)” field to get the tabs to filter by the tab name?

Every time I input text into the field and save nothing happens, and the field is blank when I return to the settings. I’ve tried enclosing the term/s in “” but same result.

I prefer the solid background fill for all tabs, and what I’m trying to do is input all the standard family file view names (Front, Back, Ref.Level, etc.) in as the filter, so that my open family files are always from that specific colour range.