Tradicantia, also called Spiderwort ranges in color from this pure white through purple. There are no yellows that I know of. It is a reliable perennial in my coastal Maine gardens. It does flop as the flowers pass and then goes dormant, which can be annoying. When it starts to flop, I cut it back to the  ground. A fresh flush of leaves will appear in a week or so. The new shoots are edible.
Dianthus On The Rocks
Woodland Phlox
Almost There
Cones
Shasta Daisy
Dianthus On The Rocks
Dianthus On The Rocks
Dianthus On The Rocks
See photo in original gallery.