Quick and no doubt stupid question about pea seeds

I have a red-flowered "White Lady" plant in the middle of the white-flowered ones, although all the seeds looked the same to me (i.e. white!) 

These were once-saved seeds from a couple of years ago, and to the best of my knowledge the nearest other runner beans being grown round here are about 150 yards away!

I think runners must cross quite easily with other varieties, especially other runners (as DD says; no effort required!)

Here's what should have bean (deliberate) a green "Enorma"



I also had red flowers on my purple beans and some produced green pods.

I bought new seed next year and the cross breeds were rubbish.

Here's what should have bean (deliberate) a green "Enorma"



I also had red flowers on my purple beans and some produced green pods.

I bought new seed next year and the cross breeds were rubbish.

Just to double check before I go and start to save anything a different colour 

The ones you had grown that were a new cross didn't give a good crop? Is that right?

I know, a bit of a dense question but there we are --- someone has to ask one from time to time