Paul, yes, the stage where you have both the yellow and the salmon at the same time is wonderful and so extends the interest of the plants.
I often recall being taken out to the rear forty by a customer who needed an identification of the "orange" or "salmon" coloured Opuntia---and even though I tried to explain, they were never quite able to believe that this was post-pollination behaviour.
Not dissimilar to the novice with Trillium grandiflorum and the post-pollination pink of the white flower, who often believe they have found the rare pink sport...oh, I could tell you stories....
