Found a photo of a Rainbow Sorbet on Better Homes and Gardens.
All-America Rose Selections 1970s-2000s
On this photo it looks like a flat single bloom.
If you compare this photo with the one I have in my Encyclopedia, you will see a difference.
If you visit the All American Rose Selection site, the Rainbow Sorbet is described as cuplike and has a 15 to 18 petal count.
Mine bloomed more than once last year even though it was planted in late June.
Every bloom had at least 15 petals.
So why does the bloom in this photo have only 5 petals?