In the pink to reddish range I have Ville de Lyon, Gravetye Beauty and another texensis hybrid, perhaps Princes Diana, that grow all in eastern exposures along a building and so only get morning sun. These all have type 3 pruning (see FAQs for pruning directions.)

I have a white Guernsey Cream that gets only a few hours of sun around late morning to early afternoon, so would probably do well as in your setting. This is type 2 pruner.

I don't grow Sweet Autumn clematis (white) or any of the yellow species type (C. tangutica) since I live on an old farm, and both of these have a bit of a reputation for spreading via seed. I have enough invasives without adding to the problem. I don't know if they would be a problem in your area.

Helios is a yellow tangutica that is a small grower and mine never seeded. All the others would be too big for that space.

Sweet Autumn would grow much too large for that space.

Thank you, thank you! I will check these out.