This is what you wrote in your 1st post about the parents :
Parents = Cock - Opaline Greywing Light Green, Hen - Opaline Greywing Recessive Pied (Same blue as chick 1)
Their offsprings are very straight forward to deduce the mutations. You would get 100% opaline greywings with 50% greens and 50% blues. The 2nd and 3rd chick are evidences that the daddy is split for blue. In addition, all chicks would be split for recessive pied since mum has the recessive pied genes.
Congratulations on the lovely chicks. They have grown nice and adorable.
Budgies aside, I wish you success in your undergraduate studies. What degree you're majoring in ?