Is the evolution of zebra really possible?

i mean can a random mutation of a normal horse really have stripes that have very uniform pattern and only be comprised of two colors? why no zebras with a pattern of three colors? why no zebras with golden or green stripes that might have provided better camouflage in savanna? Why no zebras with horizontal stripes or even diagonal stripes? If these stripes provide such a wonderful protection against predators why haven't other species also evolved similar variants? Zebra striped dogs? zebra striped birds? zebra striped buffalos?? zebra striped elephants???? c'mon don't give me a shitty answer and think you can fool anyone with your speculative guess. I need sound logical theory backed up with scientific evidence.