When I first mentioned this 'Darlow's Enigma' seedling in the July 7, 2013 post (the last photo in that post), I was certain that it didn't have a blotch. Now, nearly a year later, growing outside on a more mature plant, it is easy to see that actually the seedling does have a blotch. The blotch is best seen with the petals removed.
A new 2014 seedling shown below will probably "lose" it's blotch on the next bloom cycle (blotches fade as the weather warms up). Can you see the blotch? It is just barely visible in the center yellow zone of coloration. I suspect that the blotch will be way more visible next spring if the seedling survives.
My mentor in Hulthemias, Mr. Ralph Moore, was surprised that I got a repeat blooming Hulthemia from 'Persian Sunset' the first year that I used it. Mr. Moore had never gotten a fully remontant Hulthemia seedling. All of his Hulthemia seedlings bloomed only on "old wood", similar to most species roses. The last 2 years that I visited Mr. Moore I pointed out to him several seedlings in his seedling benches that were repeat blooming Hulthemias. I don't think that he believed me though because with his poorer vision of old age he was not able to see the faint blotches in his young seedlings.