Jeff
I double-mated last yr to clean up color a bit. Probably will not this year. I think from what I read you can single mate, with an occasional double mating to clean up color as need be
Scott yes you can single mate. However in my opinion I would continue to double mate at least until you get the type you want set in both males and females. I would worry more about the type than the color. Get the tails set in the males etc etc etc first.
Jeff is correct in stating that most Columbian breeders double mate to maintain their lines. Many of them are running 4 lines two for pullets and two for cockerels. It is one of the joys of breeding party colored birds and a reason that many people do not do this with success.
Another alternative is to have a hen or cock based line. In other words you will have really good females or really good males. With single mating it often tends to end up being a really good male line over a period of time.
http://books.google.com/books?id=Wf...+of+poultry&lr=#v=onepage&q=columbian&f=false
I sent ya an email
good luck with the birds
charlie