Question About Extreme reds

Hey guys, I'm posting this here in the hopes that someone with experience and/or supplementary knowledge on the subject sees it.
I recently obtained a little Extreme Red (Along with other stuff) in a trade for one of my Woma Pythons, I'm getting into Hognose breeding and naturally I'm excited about her. Problem is; I know next to nothing about the genetics of the trait, or if it is even hereditary at all. Does anyone know about it, is it a colour phase and can I breed for extreme red reliably? Any info would be greatly appreciated.

Extreme reds are derived from a specific locality that has been selectively bred to achieved the extreme reds you see today. (extreme reds and purple line)

The key with extreme reds is selective breeding.

So it's more the result of a line breeding type process than a morph? Okay, that helps alot, thank you.