Not locally rare. In other words, in certain locations in Canada they are common. Same goes for wild flames, or at least, the color phase that flames were captive developed from.

I think the same thing that applies to flames will apply to your orange eastern. It's polymorphism. The shade and intensity of the orange will always vary, just as the intensity, distribution, and shade of red varies with flames. You really have to raise them up to adults to know which ones are going to color up.

One can artificially select for color. That is where the reddest, most colorful flames come from. Years of selective breeding over generations, but the original pairs were Canadian WC.