They're more of a yellow background, than green, with the purple stripes, which fade away when they're cooked. (Kinda sad.) They're broader and longer than my green beans. You're supposed to pick them when they're about the length of a hand! And, if you want, you can leave them on the plant to become dried beans. But fresh like this, they're like sweet green beans, and are delicious even eaten raw.
One kind of funny thing: The regular green beans, which are growing in the bed behind the Dragon Tongue Beans, have light purple streaks on many of them. I guess some of the pollen blew back to color them up real pretty.