I can see Max! He's beautiful, and yes, sky blue opaline.
Let's see if I can explain it better:
Opaline is expressed on the X chromosome, as you know. Females are XY, males are XX. The gene only is shown visually when it is carried on all present X chromosomes. For females, they only have one X chromosome, so when they carry a sex-linked gene (like opaline), it is expressed visually. Since males have two X chromosomes, they will need two copies of the opaline gene to express it visually.
This means that males can carry opaline (be split for it) and not show it visually; when there is only one copy of the gene (on only one X chromosome), they do not show it visually but can still pass the gene on to offspring. If a male is split to opaline (meaning one of two X chromosomes has the opaline gene), there is a 50% chance that he will pass the gene on to his chicks. Only daughters will show it visually if he does, because females get their X chromosome from dad-- they have to get the Y from Mum because females have the Y chromosome. None of his sons will show opaline visually, but half of them will be split to opaline (again-- two X chromosomes mean that the one copy from Dad is not going to show up). For a male to be opaline, like your Max, his mum must
have been opaline-- each parent gives one sex chromosome (either X or y) to each chick, so the one given to him by his dad would have to have opaline and the X from his mum also had to be carrying opaline. If the mother's sole X chromosome was carrying opaline, she showed it visually.
I hope that helps somewhat-- that's probably just more confusing, but I tried