cucumber query

An important question for my gardening friends: as you may have noted, this year I am inordinately proud of my cucumbers. But several of them have turned out not green, but yellow and sour. I don't think they were once green turned yellow, and they are not a special yellow kind of cuke. How and why did this happen, do any of you know? Not enough sun? But others nearby are green and delicious. It makes this urban gardener sad to waste produce.