Hi Madas,
The bird in that pic is a grey pallid opaline combo in the blue series, so there are not psittacines, and it does not allow to know the effects of opaline on psittacines. In other parrots opaline mutation is known to redistribute melanin and psittacines, sometimes leading to an increase in psittacine expression both in intensity (deep yellow or even rose/red) and in extension, and these effects are easier to notice when melanin is removed (lutinos, creaminos or aquainos in IRNs). So I was wondering if the opaline mutation would allow the red ring to spread up to the head and show a deep yellow-red head in males .... just dreaming
The only birds in your pics displaying psittacines are the combinations with turquoise but I can not see the red ring. Were they adult males or youngs/females? In psittacula world it is written that males display a black and red ring in green series, but the pics show two green males without any visible red ring, just a kind of rose-blue sufusion down to the bird's back (?)
Cheers
Recio