Pied markings basically means that areas of colours are missing on a budgie, leaving a clear patch of white or yellow. Depending on the intensity of these markings, your budgie either has a few white or yellow patches, or ends up being nearly all white or yellow.
- Dominant pied
Photo above: dominant pied (birdaday.com)
- Recessive pied
Recessive budgies usually have mostly clear feathers, so that the base colour yellow or white remains. In general, you can find a patch of original body colour near the lower part of the belly. Adult male budgies of the recessive pied variation have purple ceres. Females have the normal white, tan or brown ceres.
The difference between a recessive pied and a double-factor dominant pied is very subtle. The best way to find out is to check their irises (the budgie on the left is recessive pied since it has solid dark eyes) or you can look at the bottom of their belly - the one on the left also has a patch of the original body colour, which is typical for recessive pied budgies.
- Clearflight pied
Clearflight pied budgies look a lot like other pied budgies. The distinguishing features here are the clear primary wing feathers and long tail feathers. These will either be yellow or white (base colours). Usually, a clearflight pied will also have some small patches of clear feathers around the neck and head.
Here is a beautiful example of a clearflight pied budgie. This one has not so many pied markings, but the primary wing feathers and tail are entirely white which makes the bird even more extraordinary. Photo from budgie-info.com
- Dark-eyed clear
If you combine recessive pied and clearflight pied together, you get a dark-eyed clear budgie. With these two mutations present, the budgie has no markings nor colour. If it's a yellow-based budgie, it will be yellow, and if it's white-based, it will be white. Their eyes never grow lighter with age, hence the name dark-eye. It's easy to confuse these budgies with the lutino/albino or double-factor spangle budgies, but none of these have eyes that remain dark all their life. Adult male dark-eyed clear budgies have purple ceres and females have normal white, tan or brown ceres.
Both of these budgies look almost exactly like albino/lutino budgies, but they have dark eyes.