Need ability to change scheme type on relationship scorecard

I created my first Relationship scorecard using a Numeric(0-100) scheme, and after a little more consideration, decided we wanted to use a Color(RYG) scheme instead.  However, the scheme isn't editable on a Relationship scorecard, like it is on an account scorecard.  

Since this is a new scorecard, it wouldn't be that big of a deal to delete and start over, but that's also apparently not possible without involving engineering.  It seems like it should be a really simple thing to change.