Welcome to YT! Congrats on getting a puppy-how exciting that must be, I am getting my yorkie sometime after the first of the year-can't wait! I personally am wanting a male when it comes time to get mine, but I was always told that when you are looking at a litter, go for the one that comes to you first-so that is probably what I will do!
Can't really help you on the color issue-but there are a bunch of nice and informative members here, I am sure someone will help ya out! ps. post pics of your baby when you get him/her!