Since you shouldn't have just one Silkie (it might get lonely and picked on by others) I think it's best to get at least 3 of every color. That way, if they are singled out by color, they won't be alone, and if they are singled out for being fuzzy, they can form a gang and protect one another. Also, if something happens to one of them, the other won't get lonely...
In chicken math terms... more is always better!!!