My John Warren clematis is in a very shady spot. Still puts up a decent amount of very large flowers every year. Good luck with your search as others might chime in as well.

Any of the 'barred' forms would work - Nelly, Bees Jubilee, Andromeda, Carnaby, Dr. Ruppel, Barbara Jackman, etc. I'd also consider any of the type ! group - alpinas, macropetalas, montanas. And any white flowered forms don't seem to mind quite alot of shade. Silver Moon would be stunning in that aspect.

GG, I'd love to find another 'Barbara Jackman' but haven't been able to find another since I lost the one I had 10-15 years ago, some of these older varieties are harder to find. I have 'Dr. Rupple' and 'Silver Moon', you're right I think Silver Moon is stunning.

My Silver Moon growing on an arch with a Akebia vine, sorry, only a closeup of the flowers.

I had Montana grandiflora in this spot just took it out, not much of a show on my side of the fence but lovely over the fence in my neighbors yard LOL. I really want a larger flower, thanks for the other suggestions I'll have a look around, see what's available. I'd really like to find one I don't already have.
Maybe I'll luck out and find 'Barbara Jackman' I did manage to find another 'Fair Rosamond' (another that does well in the shade) last year to replace the one I lost a couple of winters ago.
'Fair Rosamond' delicate color and the faint scent of violets.