Toss the light seed, there must have been a cross somehow. Possibly Dollof or Birds Egg 3. Were the light seeds in the same pods as the navy, or possibly all from just one plant?

Hi Happy, hard to tell as the vines were all interwoven on the pole but not in the same pods with the navy colored seed, thanks, will toss the light colored seed.

Annette

Annette, you could also save the light seeds, separately, and regrow them by themselves in a very isolated spot, and see if they produce any navy beans at all. If not, and if you don't get any more light seeds from your Blue Shackmaxons, then you know there was not a cross, and it was an accidental mis seeding, like a dried bean falling from a pod last year into the soil and not sprouting until this spring. Congrats on getting the Blues grown out! :)

That's a thought :).

Annette