Lovely roses. They look very healthy and happy.

My first suggestion is that unless the roses are sturdy enough to support whatever clematis you choose, you will want to add netting or wire mesh or strings tied to your trellis and French door supports. Clematis climb by twining their leaf stems (petioles) around things, so they have a tough time grabbing anything larger than a pencil in diameter.

You will want to match your clematis to both the trellis size and the rose size. Of those you mentioned, both Betty Corning (type 3 - hard prune before spring leaf-out) and Gravetye Beauty (type 3) grow to be quite large plants in my garden. HF Young (type 2 light prune after bloom) and Prince Charles (type 3 ) are perhaps better sized to pair with your roses. I grow PC with Zephirine Drouhin rose. I don't grow Polish Spirit (type 3) or Multiblue (type 2).

You can hard prune any of the clematis you mentioned, but it will make type 2s bloom a bit later and may eliminate double flowers on those type 2's that have them. I find that mother nature often hard prunes my type 2 clematis to the snow line regardless. I prefer growing clematis that can be hard pruned since that way I don't have to look at dead vines for 5-6 months of the year.

As far as colors, I think the lavenders and deep purples will go with any of your roses. Clematis reds almost always have a bit of a bluish tone to them rather than true red or orange-red, though IME the colors of most clematis vary quite a bit depending on the light at a given time. Choose what you think will look nice and you can find available. If you want to look up specifics of size and pruning, you can do so on the Clematis on the Web's search page. Put in one word of the name (it doesn't like spaces, so just Young for HF Young) and leave the rest blank. Just remember that color in clematis photos is often off, sometimes by quite a bit.

Your roses look fantastic! I lean towards Betty or Charles out of what you listed . Also agree with babs to add some material for them to climb.

For your lovely alchemist polish spirit would be great . You may like venosa violica (sp?) as well . I love what you have going on here !

I think Betty Corning would be too large. Mine covers one end of my deck which is 10 ft wide.

July 2017 Betty Corning

Polish Spirit and Gravety Beauty are also very vigorous clematis that might overpower your roses. Most type threes are vigorous growers.

For me Prince Charles has been a good bloomer without as much vine growth as the other three. Though my PC is in a part shaded area.

For reds Bourban and Rebecca have been good bloomers with more restrained growth. I do not grow roses so can not vouch how they will grow together.

My PC is in full sun and still isn't huge, so I think would be a better choice than Betty C. I agree with MNWSgal about Rebecca having a more restrained growth size, and don't grow Bourbon, so can't comment on that one.

Based on my experience Venosa Violacea, Polish Spirit and Betty Corning are much too big for those gorgeous roses. Prince Charles is smaller but I'd go with Multi Blue or Daniel Deronda or another Type II....