While whom I'm about to mention is probably too much of a star for Papermill (they generally go to "near legend that's loved by many people route), but...
I know it's been atleast once when Pearl Bailey took over the role (and hired a completely black cast) but how about for this - or for it's broadway revival (which needs to be soon), meet kind of halfway - a completely colorblind DOLLY.
Now seriously - and DON'T laugh or sneer at this....but...while just watching Pearl Bailey's amazing "Before the Parade Passes By," I couldn't help but notice some similarities in voice, expression, gesticulations, etc. to the wonderful Queen Latifah.
I would love, love, love (a thousand times over) to see Queen Lafifah play DOLLY. I think it would be remarkable!
"If you are going to do something, do it well. And leave something witchy."
-Charlie Manson