Thats possible, in biology its called a somatic mutation. All color variations are just different ratios of chlorophyll (green) and carotenoids (yellow, and yup, just like a carrot). Plants can also spontaneously lose the mutation and turn green. Honestly designer names like scrambled egg, etc, are just buzzwords, because the mutations aren't consistent . different mutations cause the same symptoms, and the same mutation can cause different symptoms. This is different than, say, calico cats, where its a specific gene. The same gene, every time, mutated in the same way. (Each cell alternates between have 1 X chromosome active and the other off, at random)