The throat spots, head and neck striations, and wing markings are a medium brown on a yellowish ground.
The most obvious distinction from Cinnamons is the red eye, which in the German Fallow is a deep ruby-red, like an Ino's but a shade darker, with the usual white iris ring when adult.
[2][3] The English Fallow has an eye of a clear bright red, without a white iris ring—a beautiful and attractive feature.
The first report of a brownish budgerigar with red eyes seems to be of a bird bred from an Olive x Greywing Green pairing by Mr Augustin of Biel, Switzerland, in 1929.
Fallows with a white iris ring appeared in the aviaries of Mr O'Brian of Newtown, Sydney, also during the early 1930s.
[16] German, English and Scottish Fallows were proved to be distinct and separate mutations by test matings made independently by T G Taylor,[3] Mrs Amber Lloyd of Walton-on-Thames[3] and Frank Wait.
It has been suggested that the German Fallow and the Non-sex-linked Ino are mutations of the same gene, a+, and hence they are given symbols abz and a respectively, but evidence for this allelic series is scanty.
In the absence of firm evidence, others prefer to assign the German Fallow mutation to its own locus, fg+ in the wild-type, with the symbol fg for the mutant allele.
That is, the presence of a single wild-type allele is sufficient to permit the full production and normal distribution of the black melanin pigment.
The pigment granules are smaller and more numerous than normal in both the cortex and medulla cells of the feather barbs[18] and are often massed together in "large drops or flakes".