You could do a white rose or purple or white clematis with low growing blue bellflowers below...I like baby's breath or perennial sages as well or perennial flax depending on height. Nepetas would look good or perple veronica but the bees like those.

I would do a search of photos on Garden Web or gardening blogs or Pinterest to see what other gardeners have combined with their red roses.

I do that too. I google images and put them next to one another to see what looks good. There are apps that allow one to do this better, but I'm not that sophisticated. : ( I've even had luck googling various roses and getting pick of them being grown together. That's how I knew Munstead Wood and Viking Queen would look good with New Dawn, as well as Fields of the Woods if I want to get it in the future.

Red is a hard one depending on its undertones, but that intensity probably calls for an equally intense tone ie a deep blue or violet or white. I think pastel lavender would wash out. White is always good with reds.

Thank you everyone for your kind suggestions. I will do some googling to see what I can find. I really like the idea of baby's breath and/or blue bells or both.

I grow perennial baby's breath and campanula among my roses and love them both. They come back bigger and better every year like clockwork. They're wonderful in arrangements, too. You'll have fun finding what's right for your garden.

Garden Mist are you still growing your Amadeus climbing rose? I am considering growing this as a large shrub if this is possible. Would the canes self support sufficiently to make a shrub from your experience?

I think you can grow it as a shrub but remember that leaving the canes vertical, you're apt to have less flowers than if they were placed horizontally on a trellis. That's just my thoughts. Other more experienced rose growers can probably help you with this.

Thanks for letting me know, Garden Mist.