My cukes never turned green..just yellow. I planted pumpkin right next to. Could this be why they’re not green? Or maybe not ripened yet? I only watered once a day but we did get a lot of rain for awhile. They seem to be growing really great just all of them never got green at all.
Since you mention heavy rain, I suspect a watering issue. Your container or soil may not be draining either fast enough. This can lead to yellowing of leaves and rotting of the fruit.