Originally Posted by Bec-eee
I'm not very understanding of the mutations thing yet. I know if any green is a dominant colour and so is blue. What about a yellow male and a white female? Lol
Basically, you have 2 base colors for budgies - white or yellow - with a blue feather on the body. So, depending on the base color and the intensity of the blue feather will determine the myriads of combinations out there.
The wild-type is a yellow base - the blue feather combines with the yellow base to visually show as Green (blue + yellow = green). The intensity of the blue varies in the wild-type's body with the most common coloration phasing from super dark (black) at the base of the wing feather to super light (yellow) to the tip of the wing feather.
If the base color is white, then all you got left is the blue feather (blue + white = blue).
Now, if the blue color is absent in the bird - then you end up with just a yellow bird (lutino) or a white bird (albino) depending on the base color.
The link that BudgieKiss sent you shows many of the variations of these color combinations.
Now, to know how the coloration gets passed to offspring, you need to know if the color is dominant, co-dominant, or recessive. There are several links on the stickies that show which budgie color is dominant/codom/recessive and a simple explanation of how basic genetics work. But I really like this basic genetic explanation on ball pythons because it comes with pictures that make it much easier to understand. The concept is exactly the same between budgies and ball pythons - it's all within the imprint of the DNA. So maybe if you read this then it will give you an idea of how mutations form.
So, once you find out which budgie color phase is dominant/codom/recessive, then you can apply that to the genetic lesson above to have an idea on how different coloration on the offspring is formed from two differing color parents. For example - the green color is a dominant color while the blue color is a recessive color. That means that you need 2 birds with at least one blue gene (a green bird with a blue parent or a blue bird) to breed to come up with a blue bird. But to come up with a green bird, all you need is one green bird (both parents are also green) and it doesn't matter if the other bird is blue or green, all the offspring will be green.