We have two lovely shades of violet clematis. The variety of clematis in the first and third photo is called "Blue Ravine." This vine has huge lilac-blue flowers with pinkish highlights and contrasting red centers.
The clematis below is Starry Nights Clematis. It has spectacular dark-violet, star-shaped flowers with pinkish/red stripes. Most clematis do well in full sun to partial shade.
I will say, however, that our three year old clematis vines were planted in partial shade and have had a harder time {than our full sun clematis } getting established. All our clematis were planted next to a fence and are great climbers.
I love these blossoms that are as big as a salad plate. They are hardy, once established, and become a mass of blooms all from late spring to early fall. So very pretty.
I hope you're able to enjoy the blossoms in your neck of the woods today!