From Left To Right- (1-2) Light Green, Opaline (3-4) Sky, Opaline.

From Left To Right- (1-2) Dark Green,, Opaline (3-4) Cobalt, Opaline.

From Left To Right- (1-2) Olive, SF Violet, Opaline (3-4) Mauve, Opaline

From Left To Right- (1) Grey Green, Opaline (2-3) Grey, Opaline

Body Color: Opaline is a slightly diluting mutation. A Opaline budgie will have an even shade of up to 10% diluted body color (body color will vary depending on whether they are green or blue, and if they have any dark factors) on their chest, breast and rump where it will be the darkest.

Head Barring Wing And Throat Spot Markings: Black with yellow or white edging along the tips of each feather in addition to the body color, with solid black throat spots. They will have a noticable V area on the head/shoulder area of lighter barring and body color. The primary flight feathers will have a larger white area when compared with a normal wing.

Cheek Patches: Violet

Main Tail Feathers: Deep blue. Many also have white or yellow on the main tail feathers (see help to identify for examples).

Feet And Leg Color: Blue to grey

Eye Color And Iris At Maturity: Black eyes with white iris.

Mature Adult Cere Color: Medium to deep blue in males,. Light blue/white to tan in females depending on if they are in breeding condition.

Genetic Information: Opaline is sex-linked (located on the x chromosome) needing only one copy of the gene to be visual in a female, and two copies of the gene to be visible in males. For a female to have this mutation she must show it visually, while a male can have it in a split (hidden) form.

Cheek Patches And Main Tail: Depth of blue in tail and cheek patches will vary with dark factors, as you can see in the above link to tail and cheek patch photos.