What you are seeing is typical of beans, but is confusing because it represents something you have not experienced before. The seed testa of a bean is maternal tissue, meaning that it is derived from the mother plant and therefore does NOT represent the genetics of the seed inside. For this reason, the original crossed seed looked just like your Uncle Steve's because it had the seed coat of the mother plant. For the same reason, when you grew that crossed seed last year, the testa colors represented the color of the maternal plant which grew from the f1 seed. This year growing F2 seed , you recovered the seed coat color of both original parents, the seed coat color produced on seed from the F1 plant, plus a few with mixed traits like blue with swirls etc. It will get really interesting if you grow some of segregating seed next year because recessives recombine and show up in seed size, testa color, flavor, etc.
The way I work from that kind of cross is to find the individual plants with traits I want to propagate and grow them out. On average, about 3 plants out of a hundred are really worth saving and growing because they carry a unique combination of traits.
I will give a really good example from my growout this year of a cross between Fortex and PI207373 (a small black bean with intense purple pods). I am attempting to bring high disease tolerance from PI207373 into a long high quality bean like Fortex. This year, I grew a row with roughly 100 F3 plants. F3 is where most of the recombination of traits shows up with beans because you can see the recessive traits. I got plenty of purple pod beans and some with green pods, but I also got two totally unexpected beans. One is a beautiful red snap bean, the other is a yellow snap bean. Neither parent showed red or yellow in any way. But when I made the cross and started growing out the offspring, the result was this:
http://www.selectedplants.com/miscan....29.beans3.jpg