There are several types of fallow varieties, but in general, the fallow's head, wing, and tail markings are brownish. The body color is gradually diluted and is most visible on the rump. The eyes are red (some varieties do not have a pink iris, others do) and the cere of the male fallow does not change normally. Adult male fallows have purple ceres. Adult female fallows have the normal white/tan/brown ceres. This is a very beautiful specialist variety and is only seen in exhibition budgies.

Basic Genetics:
Normal - dominant
Fallow - recessive

For more information on Fallow budgerigars and their genetics, visit Bonsai Fallows

photos courtesy of Bonsai Fallows
The fallow variety has brownish markings, diluted body color, and red eyes.