I have never seen bow color ever mentioned in the yorkie standard.
No, it does not matter what color and you should never get penalized for having any other color. You can choose which color. Red is the most popular and does help with making the gold and dark - seem to show up better - jmo. I also try to have my lead match my bows and will even try to make sure it goes with what I plan to were in the ring. So go crazy with your colors and even designs! Besides you have a puppy and go really crazy!
T.
P.S. I had a beautiful teal blue on one of my females I was showing once and the judge asked if it was a boy - I guess he wanted to make sure I was entered in the right class and the blue bow threw him off. But I liked it!