Suggestion for Scope Colours

Would love the option to change the scope colour from a block background fill to a left-hand line highlight.

For instance, a scope's file tree gets a full background colour, which can be distracting - but making it a more subtle colour isn't always better. What would be nice is if there was a Background Highlight/Line Highlight option. So instead of full background colour, the file tree would have a coloured vertical line to the left of it.

Files in the top bar and in the "Search Everywhere" popup could work the same, having a left border colour.

It would only have to be 3 or so pixels wide, and I feel would keep the usefulness of the scope highlighting, but remove some of the distraction of it.