Dark Bees?

The bees in E Hive

The late swarm which I caught at the end of July has settled in. It appears to be vigorous and there were many bees flying today. I noticed that they were darker and smaller than I remember from the collection.

It may have been the overcast day which made them look darker. I may be mis-remembering. Seven weeks have passed since I caught the swarm so it's possible that these are new brood.

I'm hoping that these are not just near descendants of Buckfast bees. There are plenty of those around, and it would be nice to find hardy bees with a bit more genetic diversity. The ideal would be to find a strain which is Varroa tolerant.

The photo in this post also shows the block of propolis which the bees built over part of the doorway. Like D Hive they really love slapping a bit of propolis about the place.

EDIT 2/10/2016 - These aren't dark bees. They're just bees on an overcast day. It was a bright day today.