As far as broodiness goes, you do not need to have a rooster or the eggs to be fertile for a hen to go broody. It largely varies by breed, but I think it truly varies on individual birds and conditions. For example, Silkies are widely known to go broody, but my three year old hen has gone on maternity leave only three times. Also keep in mind that breed and genetics determine egg color, so for example you can have Buff, Black, or White Orpingtons or White or Golden Laced Wyandottes, but they would still produce the color associated with the breed (brown), in this case Orpington and Wyandotte.
