The mutation often brings about a notable change in the bird's eyes, which turn a striking ruby red colour, accompanied by a white iris ring in adult birds.
Furthermore, male fallow budgies exhibit pink ceres, while females have their usual whitish/blue when not in breeding condition and brown when in condition.
Fallow budgies display dark violet cheeks, and they can have brown markings on their throats.
Another distinctive characteristic of fallow budgies is the alteration in their body colour. The mutation leads to a reduction in black eumelanin pigments, resulting in a faded appearance and a prevalence of colours based on white tones.
One distinguishing trait observed in fallow budgies is the occurrence of brown markings on their body and wing feathers. In contrast to other budgies, they lack any black or additional markings on their body or plumage.
Although fallow budgies commonly exhibit a white iris ring, its presence is not universal. Additionally, the extent of black color reduction can vary across different variations of the mutation, resulting in distinct features. For instance, Scottish fallows may not display the white iris ring.
There are several recognised types or variations of the Fallow mutation in budgerigars. These variations can result in different visual characteristics and colourations. Here are some of the commonly recognised types:
Scottish Fallow: Scottish Fallow budgies are characterised by a lack of the white iris ring, which is a common feature in other Fallow variations. Sometimes you may find that Scottish Fallows have grey/silver iris, or different shade of pink.
English Fallow: English Fallow budgies are another variation of the Fallow mutation that displays reduced black eumelanin pigment. They often have a lighter body coloration with a subtle or minimal presence of markings. Solid pink eyes, with no iris.
German Fallow: German Fallow budgies are recognised for their distinct coloration, often white or yellowish body colour. They may exhibit unique variations in colour patterns compared to other Fallow mutations. Colour (blue) only seen in the rump area. White iris ring around eyes.
Dun Fallow: the rarest type of Fallows. The body colour is unchanged (e.i. blue, green or grey), looking like normal budgie, but wings feathers have brown markings and eyes are red.