Love the phlox idea.
As I drove I thought about the iris and the green of the stem could easily work for another color echo.
I've read that the lighter heucheras (like the amber and peach family) want shade while the darker ones can take the sun. Since I've lost every light one that I had in sun I can't test it out but the dark ones do well for me in full sun. Purple Petticoats and Palace Purple retain their color. I do believe those spots could fade to tan as Julia mentioned - great thought, Julia. Mine hasn't had the problem but it's in a spot that doesn't get the hot afternoon sun.
