Dried Beans Vary
Hopefully, you can shed light on our gardening question. We had a huge crop of pole green beans this year and got tired of freezing so we let some of them mature on the vine. To our surprise, the dried beans look like two different types of beans. Unfortunately, we did not save the seed packet so I can't tell you the variety. Why would green bean plants that produced fresh beans that looked alike produce two different types of dried beans?
Beans are 'self-pollinating' but if you have more than one variety (and it's not just limited to your garden) then the resulting seed may be different. Since these are pole beans, the white ones are likely the 'self-pollinated' and the tan ones are likely a cross from some other bean. Maybe you have a new hybrid! I found an interesting article discussing 'open pollination' that my help further your understanding. http://www.garden.org/subchannels/care/seeds?q=show&id=293