There are green beans and then there are yellow (wax) beans, but what is this? Same seeds as the others, which are all green, lol. Must not have any chlorophyll and probably won’t grow, but it did manage to get itself up out of the ground and produce a set of primary seed leaves, and seems to have another little set of leaves coming. It’s a mystery………….
Sarasin's thoughts....... 
There’s a bean blight called “Yellows” though I’ve never seen it. Could it be?
I don’t know, but I’ve never seen anything like it before, and this is the only one, all from the same group of seeds. I have some others that were planted way earlier and are already climbing my trellis and I thought I’d throw a few more seeds in for good measure in another spot, and there it is. Interesting…….. How does your garden grow? Hope all is well with you!
Must be a different seed.
Something was missing from the seed and it didn’t grow. It’s neighbors are now twining on my fence tho.