I had another look at that hive yesterday, and they now have brood on three frames, and they're into comb drawing mode. For the first couple of weeks, they were tearing down comb, and I'm not sure why. Bees often tear down old, black combs which the beekeeper ought to have removed long before, but these had only been drawn a couple of years ago, and there was nothing obviously wrong with them. Other combs of the same age or older have been accepted without problems.
Rebsie said she's found two different varieties circulating as 'Kent Blue'. That's not unique; there seem to be several King Tut's. Here are a couple of not very good pics of mine. The small, dimpled, olive-green seeds with purple speckles look right; it's about four feet high, and a bit overshadowed by taller peas. As you can see from the second pic, there are splashes of purple at the leaf bases. It remains to be seen whether the pods become sickle-shaped and knobbly.
This is Bijou, a giant sugar pea from Real Seeds. It's an extremely vigorous grower with these hooded, deep purple flowers. It's going to be interesting to see what it turns into!
This one is Ezetha's Krombek Blauschok. I don't know the origin of this one; it could be old, but there are no old records of the name so it could be quite modern. Over there the purple podded varieties are known as Capucijners, after the Capuchin monks who bred improved field peas in the 15th Century.