It is very rare in my experience for a solid color bean to produce stripes. It is also rare for a single plant to have beans with different colors, shapes, etc, unless those changes are a cross.
One pink bean in a pod with black beans, or a striped bean in a pod with solid colored beans, in my experience is likely to be a cross. I can’t say for sure that the orange in a few beans on a plant which otherwise produced only solid colored pink beans was a cross, when it was planted beside a striped orange bean, but logic says the color change was related to proximity.
The simplest way is to grow out the population. The pink and orange stripes persist, the purple “pinto” stripe, and so on.
Bean shape is another thing I watch. In the second generation you may find that the shapes start to reflect one parent or another. I have not been able to prove this to my satisfaction in the first generation, but there are often mature beans whose odd shape doesn’t match the other beans in the pod.
As I was recently reminded, the science of genetics is rapidly changing and even those who have made this their life’s work are often stunned at the things being learned and the changes to long held beliefs.
