Fabulous photos ckat! Just glorious!
I have never seen, read or heard of hummers nectaring on sunflowers. And while they prefer red or orange blooms - or at least those are the ones that bring them in - I have seen them on every color of bloom. Here's what I always read or heard ~~~~ that the bloom has to have a certain channel or shape for them to be able to nectar on it. Your photos just about prove that info. wrong ckat. The only other thing I could say is maybe it was picking bugs from the sunflower????? You would be able to tell that better by the length of time it spent in one position.
