This colouring along with Chocolates are considered to be incorrect to the breed standard for the Yorkshire Terrier. There is more info on colours on the Yorkshire Terrier Club of America which is the parent club found at
www.ytca.org
You may also want to read the info provided on this link
http://members.aol.com/CYorkie/BiewerTriColor.html
I have no intention of getting into debate, only to present the facts. Anyone can think what they wish.
BTW 6 months is too young to ever consider using a male for breeding You wouldn't use a female at that age and neither should a male so young be used.