Hi, years ago (20? 20+?) when I had a small nursery I bought in some clematis. One of them opened white, then over a couple of days, developed purple shading and then was all purple. We sold out of them immediately, and then we couldn't get any more of them. I've forgotten the name of it, and I've been cruising whole supplier lists trying to see if anything rings a bell, but can't find anything close. Does anyone know anything about this clematis, or did we imagine it?

Thanks!