Red Factor Corn Snakes
The Red Factor morph replaces the orange in a corn snake's ground colour with red. Because the colour builds over several sheds, a hatchling can undersell the adult. Coral and salmon labels have not always matched how many copies an animal carries, so check before paying for two.
About the Red Factor gene
The colour gene Red Factor changes the ground colour of a corn snake to red. It replaces orange with a deeper red wash across the whole animal. This gene leaves the pattern alone and adds to whatever it is paired with. For this reason, it sits behind the pink snows and the deep red cayenne fires.
Appearance
A red factor corn features a normal pattern of darker saddles with black borders on a lighter ground. Only the colour changes, as orange gives way to a red wash across the body. More red is found on the head than a normal corn. This red is strongest at the base of the neck and on the head in hatchlings, and it saturates and spreads across the head as the snake grows. The tail follows the body. The eyes are usually a deep reddish orange to match the saddles, with a black pupil. While the belly keeps its checkers, red often bleeds into the tail end or into the checkers themselves. In the most extreme animals, nearly all the black in the checkers turns dark orange or red.
A young animal can undersell the adult because babies hatch with only a little extra red. The colour builds over several sheds. Some lines show it within weeks of hatching while others take months. Two copies make a redder snake still. On a snow the gene reads as pink, and the two-copy salmon snow is a deeper, brighter pink.
Genetics
Red Factor is an incomplete dominant gene that most keepers still call "co-dom". One copy shows, and the two-copy form, Super Red Factor, is redder. A single-copy animal is called a coral while a Super Red Factor is a salmon in current trade use. Red-enhanced lines were sold for years using names such as cotton candy, cayenne, bubblegum and strawberry (a line name, not the Strawberry gene). These older coral and salmon labels did not always follow copy count. You should ask the seller how many copies an animal sold under one of those names actually carries. Named combinations include coral snow and salmon snow, with amelanistic and anerythristic; coral ghost and salmon ghost, with anerythristic and hypo; and the cayenne, a fire (amelanistic with bloodred) carrying Red Factor.