In my experience, having hatched chicks and raised started birds for a more urban backyard market for several years before scaling back and raising what makes me happy, people want whatever you don't have. Painted silkies and various polish seem to be the hot thing now. Fancy colored orpingtons and wyandottes were big a couple years ago, then there was/is the Ayam Cemani craze. The Brahma videos circulated, and people that had never heard of on had to have one, like a year ago, but now people around here are giving them away on the swap lists. (I was tired of Brahmas ten years ago.) Pick a good useful breed that lays a lot of eggs and is hardy in almost any type of management system, in a color that pleases you, and raise them. Chasing the next fad is almost impossible to get in on the right end of the market. By the time you get your breeding stock ready to produce, the next fad will have hit.