The dark color of the blue morph Snow Goose is controlled by a single gene, with dark being partially dominant over white. If a pure dark goose mates with a white goose, the offspring will all be dark (possibly with white bellies). If two white geese mate, they have only white offspring. If two dark geese mate, they will have mostly dark offspring, but might have a few white ones too.

The oldest Snow Goose on record, a blue morph, was shot in Idaho in 2020. It was 30 years, 8 months old and was originally banded in Arizona in 1990.