A pure Welsh Harlequin can have facial striping, It doesn't mean they are mixed, just not good color quality. I have a pure Welsh Harlequin that has blue wing bars like a silver, but she is dark chocolate brown!
When they are first hatched, the girls should have pinkish/yellowish bills and the boys will have black bills. USUALLY. Sometimes you get a weirdo in the group OR you end up with a bloodline that doesn't have the genes that allow for color sexing.
When they are older, the boys should have an...