I don't know what these beans are called. I called them a French Shell Bean. A quick internet photo search came up with one listing for "Tongue of Fire" beans. I bought some at the grocery store last fall as a fresh shelling bean. We enjoyed them so I set a few pods aside and dried them to plant this spring. We got another meal out of them and I've set aside a few more for next year. I found that they are best harvested when the pod is pink and white, then the beans inside are more mature. The pods that had more green, had pale green beans. They all turned white when we cooked them with some tomatoes. They were lovely and tender.
These are Scarlet Runner Beans. When I planted them I don't remember noticing that the beans were purple and black. I think they will fade as they dry. It was a wonderful surprise to open the first brown pod and find lovely lavender and black beans. There will be more of these soon.
Here's an article about cooking shell beans. It makes me think that maybe I should cook seed and cook my pole beans that have gotten too tough to eat as green beans.