Adult Yorkshire Terriers whose coat colours deviate from the standard, or that have woolly or extra fine coats, are still Yorkshire Terriers. The only difference is that atypical Yorkshire Terriers should not intentionally be bred. In addition, care may be more difficult for 'woolly' or 'cottony' textured coats, or coats that are overly fine. One of the reasons given for not breeding 'off-coloured' Yorkies is that the colour could be a potential indicator of a genetic defect that may affect the dog's health; a careful health screening can clarify if any health risks exist. Coats may vary in colour. For example, a mature Yorkie may have a silver-blue with light brown, while another might have a black and creamy colour.