Red white runner beans

[ameno]

My white Spagna Bianco runner beans are germinating now (I was forced to grow them from seeds save for eating from last year, as the bought packet all rotted instead of growing), and I noticed something. A couple of the seedlings have red-ish leaf veins, like the normal scarlet runner beans have (white ones are usually lime green), despite growing from a white seed.
I grew these beans last year fairly close to normal runner beans, so there's certainly a fair chance they could have crossed. And if the red pigment is being produced in the leaves, they there's a good chance it will be in the flowers and seeds, too.
What I want to know is if anyone has experience of this, and what sort of beans I can expect from these plants? Will they all be purple? Will they be mixed?

[muckdiva]

Don’t know, but am curious to find out

[ameno]

An update on my crossed beans.

As said above, they were grown from white seeds, but all the ones which had red leaf veins did indeed turn out to be scarlet-flowered with purple and black beans, just like normal runner beans.
They weren't exactly the same as normal ones, though. I think the beans have turned out prettier, for starters (they are a slightly different shade of purple, have more black on them, and the black speckles are more evenly distributed, rather than being in blotches. They have also inherited the shape of their white parents, being more wide and flat, whereas the other parent (Enorma) has a cross-section which is rounder and narrower.
Perhaps most significantly (seeing as I'm growing them for dry beans), they are bigger. They are not quite as big as their Spagna Bianca parents, but they are definitely larger than most normal scarlet runner bean seeds.

I have decided to save some for growing next year, and see what the next generation ends up like.

[ameno]

Here's a comparison pic.
Left is Enorma, right is Spagna Bianca, and the middle is their offspring.
Note their shape and size is much closer to Spagna Bianca (although not quite as big), and they are a softer purple than the Enorma.

Also, the variety Enorma is so named because it has particularly long pods. The individual beans are no larger than the average runner bean.