We have dominate genes and recessive genes . Depending on how they paired up before birth determines the color. Genes can also play a role in your ferrets health and body structure. Again, all parts need to work together. Like the leaves on a tree, some are more green, others are lighter in color, this depends on the genes that were carried to that part of the tree limb.
Ferrets come in a variety of colors and patterns, ranging from self to fine point.
Depending on what genes the ferret carries and where they're located is what color the ferret will be. Your two most common colors in ferrets are the Sable and the Albino. From there depending on the mutation of each gene and where it is located on the chromosmes it branches off and can form a variety of colors and patterns. The color tree below is an image map with clickable links that will take you to pages explaining each area. The information that you read here regarding the genetic status of the ferret is mostly theory.