Dreamer the only way is to keep the pet quality drake away from the hens for about a month before you collect the eggs you want to hatch. There was a period that I kept two pens, one with my hens and one with my drakes, but I put the drake I wanted with the hens I wanted him with for a while each day and that worked out fine. I didn't want to keep the one drake by himself all the time.
Just to add to my original post, & you can visually see this in KansasKid second diagram, you could breed both sexes in both colour forms from the one breeding pair of birds, but all silver drakelets will be heterozygous silver/gold phase (D+/d). Do to the following:-
Mate a "pure for brown" gold phase drake to a silver duck & you will produce heterozygous silver/gold (D+/d) phenotypically silver drakelets, & gold phase ducklets (d/-). Select one of these heterozygous silver/gold phenotypically silver drakelets (D+/d) & mate back over a couple of gold phase (d/-) ducks. You will produce your silver (impure, D+/d) & gold (d/d) male, & silver (D+/-) & gold (d/-) female progeny from the one pen. But remember, the silver drakelets will carry hidden one dose of the sex-linked recessive brown dilution gene hidden (D+/d).
I know this is an old thread, but I was wondering, at what age can you tell the colors of the ducklings? How do you distinguish gold and silver ducklings?
75% can be accurately sexed by dark bill colour (drakes) vs light bill colour (ducks) on the day they are hatched. You will need to wait 2-3 days to sex by down colour.