They are probably fine to eat, no disease. Common bean pods have varieties that are green with purple mottling like that, or all purple. All cook up fine, usually the purple fades when cooked.

You just have to figure out is this some color mutation or maybe a wrong seed got mixed in the packet. Do multiple plants have purple mottled pods? Romano pods should be flatter.

.Sometimes pods can show markings depending on conditions, but those are quite marked.

BEAN, DRAGON TONGUE BUSH , an example of a purple marked yellow pod

I grow Rattlesnake pole beans, and they look like that. They're delicious and turn green when cooked.

The beans in the pic aren't shaped like Romano - perhaps another variety snuck in? I've had different beans come up sometimes amongst the variety I bought. They might be sports.

I have four plants, three have just a few purple marks on them and the one pictured is the only really bad one.

I split the pack of seedlings from the nursery with a friend and theirs didnt turn purple.

Are you positive they're not supposed to be like that?

Again - they do not look like any Romano beans I've ever seen - even purple podded ones. Pods look very round - like regular beans, not wide and flat like Romanos are supposed to be.

A tag might've been switched...