Not a regular post, but there have been questions about when beans are ready to be harvested. This post aims to help.

These are Mrs Lewis's Purple Podded Climbing French Beans. The one on the left is dark purple and the beans can hardly be felt so it is good for eating whole without shelling. The one on the right has lost all its purple, the beans can be felt hard, and the shell feels dry and crisp. It is ready to harvest as seed for future sowing or as a dry bean for soaking, cooking and eating.
These are also Mrs Lewis's but no longer purple all over. The shell will be tough but the beans inside good for eating fresh. The beans inside are not mature enough to be viable as seed beans for future sowing.
These are Cherokee beans. They are a fat climbing bean. The three on the left are good for eating, still really green with beans showing. The two hanging at the bottom of the picture have lost their deep green colour so the pods will be stringy but the beans inside will be good to eat fresh though they are still immature and not viable for future sowing. The ones above them are brown and the pods dry and crisp. These can be used for seed to grow next season or as dried beans to soak, cook and eat.
These are Jesse Fisk dwarf french beans. The green one at the bottom of the picture is good to eat pod and all. It is still fairly flat and green all over. Three of those above it have become speckled with red which makes the pods tough but the beans are good fresh (but not mature enough for seed saving). The centre one has lost all its red and green, has dried off and is ready for harvesting or eating as a dried bean.