I think opal dose not come in one Template
may be it comes all over the body or on a part of the body (neck - wings - tail)
the black hen .. we can recognize the bronze shadow on the neck and on internal part of the each father.
we can recognize the different between these tow red pigeons
with some light colors like red - yellow - ash and silver opal gene impact dose not be very clear ( on some dark colors like black opal impact is more clearly).
this is one of my black opal pigeons
Thank you all for this interesting talk