Base colour

Black, red and yellow are the starting colours beneath a gecko's patterns. Black can cover a red allele, so a black-looking gecko may still pass red to a hatchling. Yellow is part of the base too; the combination of inherited colours helps decide the shade you see.

On a gecko's Genetics tab, read the base entry before choosing parents in Pairing. If the red allele is confirmed under black, the line can show B/r. If it has not been confirmed, treat red as a possibility, not a promise.

For a B/r × r/r pairing, the black parent can pass B or r, while the red parent always passes r. Each egg has a 50% chance of B/r, visibly black while carrying red, and a 50% chance of r/r, visibly red. A parent with one yellow allele paired with one without it has a 50% chance to pass the yellow allele to each egg; yellow can change the visible base. Compare the Black Base, Red Base, and Yellow Base library sheets before choosing a colour goal. The inheritance examples show how to use a per-egg chance in a breeding plan.