Suggestions for clematis?

[greenbean]

Hi all!

This is definitely totally off-topic, but I was hoping people could give me some suggestions on a clematis to grow.

I want to allow it to climb through a star magnolia, which is about 12 feet tall (though it has begun to produce more upright growth recently) so the clematis shouldn't get more than 15, maybe 20 feet tall. The site stays moist even in our dry summers, and it gets sun until perhaps 11 a.m. then it gets varying degrees of filtered to full shade the rest of the day, so not a lot of sun. However, the magnolia blooms and grows wonderfully every year, so there's plenty of sun for it, at least.

Now, here's the tricky part. While I am looking for something to add a second season of interest to the magnolia, meaning a summer or fall bloomer, I am also interested in fall foliage color. Since everyone focuses on clematis blooms, it's hard to find information online about foliage color. One of my horticulture professors recently showed me a picture of Clematis tangutica with beautiful burgundy fall foliage. Since the magnolia turns yellow in fall, this would be a good contrast, but I wanted to hear some other options too.

Of course suggestions of other vines are welcome, too. Keep in mind that winters here usually see several days of temperatures in the high teens (lowest I've ever seen was 16 or 17 degrees F) and our summers are dry (though the site in question is moist to wet year-round).

Thanks for any suggestions! Sorry for the lengthy explanation, but I wanted to give a clear picture of what I'm looking for and my conditions.