I got this from a local garden nursery here in 2010, and I have not seen tri-color ones in our local Home Depot either. Maybe try a fulltime garden nursery, not the big box stores..maybe they have some leftover ones from previous season. I remember I got this one as leftovers already.
When it is in shade, it loses its tri-color feature..try to look again, in shade they look like this:
As summer comes, it gives these lovely blooms:
