Much confusion here. P. 'Colin Tilley' is listed as a zonal in The International Register and Checklist (orange with a white center). This Regal is very lightest lavender with raspberry blotches and dark purple almost black veins on the upper petals. Unfortunately, last year Colin Tilley changed himself from palest lavender to orange-pink. Over a period of a month, all the plants we had changed color by themselves! This year the flowers came out white again, but they look like they might want to change to orange-pink again. We are watching them nervously.