Brown Cucumbers, Rotten or Not?

I was intrigued by the variety of brown cucumbers listed on Heritage Harvest Seed companies website called Kaiser Alexander. I have never seen or eaten a brown cucumber. Unfortunately or fortunately depending on you take, they are only brown when they are overripe and going to seed. It is very odd looking as many cucumbers turn yellow when overripe. Check it out for yourself.

I've always wondered why we ended up with the characteristic colors of vegetables in the grocery stores, especially when most crops historically had several color variations maintained in heritage varieties or in the wild. Is it due mainly to the vast crop monocultures, marketing and customer preference or just a system that was setup and never changed? Maybe people and society at large forgot that corn, potatoes, and carrots and many other crops can have multiple colorations, shades, and hues.