Dumb question but, If you only have one rooster and you are only hatching eggs from one hen, how much variety will there be among siblings. Will they all look the same when they grow up or will there be big differences. I know that people talk about split half and half in some colors.
The amount of variety can be very little or vary dramatically. If both birds are homozygous (pure) for all genes relating to chicken plumage, then there will be a great deal of similarity between the chicks as they will all get the same set of genes from each parent. However, if each parent is heterozygous for all genes relating to plumage colour, each chick that parent gets will have a different mix of genes: some will get one allele and others will get the other. Combine that with another parent who provides the same diversity to its offspring and well, you could well end up with no chick looking anything like another. So, those are your two extremes. For any random birds you will probably end up somewhere in between and not at either extreme. If you have two birds who have been bred to their variety for generations you are pretty close to the first extreme of all chicks looking alike.