Rainbow is a combination mutation of a blue based budgie, opaline, clearwing (or fullbody greywing) and one of the yellowface mutations.
Body Color: Sky, cobalt or mauve blue with full body color (10% or less dilution) depending on the specific dark factors.
Head Barring Wing And Throat Spot Markings: White to medium grey
Cheek Patches: Medium to deep violet
Main Tail Feathers: Grey with body color suffusion
Feet And Leg Color: Blue or 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.