Blushing Crested Geckos
Blushing puts a pink to red flush on a crested gecko's chin, throat and cheeks, and it shows best once the gecko fires up. Breeders read it as a sign of red base carried out of sight, so ask for a fired-up photo before you buy.
About the Blushing gene
Blushing is a head colour trait: a pink to red flush under the chin and down the throat, with red or rosy cheeks. Breeders care about it because it is one of the few markers in crested geckos, and it points to red base carried out of sight.
Appearance
The cheeks go rosy or red, and the colour runs around the throat and under the chin. Judge the flush from a photo of the gecko fired up, not a pale daytime shot. The shade runs from pink to red. It is not a look of its own: it sits on top of whatever the animal already is, and turns up on other morphs and on patternless animals.
Genetics
Listings use two names, Blushing and Pos Blushing. Blushing marks a gecko heterozygous for red base, the recessive red that can come out of animals showing no red at all. The link shows most in lavenders: lavenders have produced reds, and red to red pairings have produced lavenders with red throats and blushing cheeks. The cause is still open. A competing idea is that hypo drives the red pigment, and phantom hypo yellow base animals that fire down dark but fire up red where the dark pigment was keep that question alive. You will also see it listed as Blush, Blushed and Red Throat.