[QUOTE=Lorraine]<<Generally, a red legged Yorkie is usually introduced into the breeding program to bring back the true blue and gold colors when a line is getting too washed out (more silver than blue).>>
This is not true at all if you ask knowledgable long time show breeders, ie someone in it longer than 25 years.
Information obtained from
http://dandugmore.netfirms.com/color.html by Joan Gordon - over 50 years in breeding and considered one of the most knowledgeable breeders and judges. About Joan Gordon:
Joan has been showing Yorkie's for 50 years this year. She orginally bought and finished 5. Finished 19 American Bred 54 imported and 168 homebred Champions. She has written two books and collected every piece of Yorkshire Terrier Memorabilia she could get her hands on from all over the world. A trip to her home in Glenview Illinois is a delightful experience and education in itself.
She has been crowned the "Godmother of all Yorkshire Terriers" and certainly the breed would not have been the same with out her loving hand.
Years ago Mrs. Annie Swan, of the Invincia Yorkies, told us to keep one in our breeding program. She said everyone kept a so called "Red". They occasionally appeared from silky coated parents. No one ever showed them, but since they had the ability to return color pattern to it's proper boundaries and the ability to darken the color of a lighter dog when bred to them, they were on occasion bred in. Bred to cottony or wooly texture they usually have little effect. Bred to silk texture they improve color. Bred together they usually produce themselves and occasionally a lovely colored silk dog - but this is the exception.