**edit: sorry my brain went out the window on this one.
@Ridgerunner correctly explains below what I failed to explain in this post! Do not pay attention to what I have said here**
Ah yeah, sorry I don’t know what the best testing options would be in S. Africa! But maybe they are decently priced there too.
If your roo hatched out of a green egg, then he DOES carry at least one blue egg gene. So if you breed a roo from a green egg to a hen that lays green or blue… just say that the hen has only one blue egg gene and the Roo does as well - the offspring percentages would be 25% brown/white/tan egg and 75% blue or green egg. So if you want more green/blue layers your best chance of getting some is to breed a roo hatched from a blue or green egg and a hen that lays a blue or green egg!
If you have a fluffy bearded boy that hatched out of a green/blue egg, breeding him to your blue/green egg layers will give the best chance for the next generation to be bearded blue/green layers
In future generations, band chicks that come out of blue or green eggs so that you can ID them as roosters and know that they carry that gene.