The flame gene is a simple co-dom, I could breed her with any sirtalis sirtalis, (Hybridization is highly frowned upon in the Thamnophis trade) male and get a percentage of flames in the litter.
Put two flames together and get an all flame litter. There is no such thing as a "het for flame" either they are red, or not..
Cross a flame with an erythristic and get this..... (unfortunately another female, so I can't cross these two) as she ages the scales on the back of the snake gradually turn more red. This gal gets redder and redder with every shed, I also had her brother, he was more of an orangish red, but he passed away at 5 months old.
The orange one...