Interesting. I, too, planted a large area with this last summer. Are they all in the same amount of sunlight? I notice mine that have shrub shade are not as dark. But I have not seen any all green ones.

I have one patch where one part of it gets more sun than the other. When it was hot and sunny last summer, those in more shade are as you described. But, so far this spring, they are all doing well with the dark color and bright blooms, but the green ones I mentioned in my original post are still a plain old, drab, ugly green, with no blooms. I moved them to their own separate patch, like orphans. We'll see what happens to them as the seasons progress.

I think you are right. They are either seedlings not true to form or reversions. But who knows, they may have some great quality that is worth saving, in a plot separate from the others. I will have to keep an eye on the ones I planted.

With reversions/seedlings....I have a section of Husker's Red Penstemon. A plain green seedling showed up a few years ago. I moved it but let it live. It turns out to have really beautiful flowers, larger and nicer than it's parent. I actually prefer it.