My pole and bush beans are growing in containers and potting soil. Originally the leaves were dark green but now have turned yellow. They get plenty of water and sun and there are quite a few blossoms.
Bean Leaves Are Turning Yellow
Certified GKH Gardening Expert
They may need nutrients or they may need even more water. Container plants are very reliant on people for their water. If temps are above 90F, as they are in many parts of the country - you should be watering at least 2X a day, 3 if you can manage it.
This article will have other reasons a plant gets yellow leaves: