I swiped the following post from an older topic I found and copied it because it has what I consider very valuable information for any one working with corn.
Joseph Lofthouse wrote:There are 4 different areas of a corn kernel that might contribute to the final color of each kernel. They might combine together, or a more outward layer might mask a more inward layer.
1- The pericarp is the outermost layer. It is maternal tissue only, so there is no xenia effect. There are no guarantees either way that it will be inherited by the offspring or not. A dark pericarp often obscures underlying layers. Colors when present are typically reds, browns.
2- The aleurone is the next deepest layer. It is a xenia layer, therefore colors may be influenced by the pollen donor. Colorless/transparent is the most recessive. Colored kernels on white cobs may be due to the pollen donor. The pollen donor might only contribute an epistatic gene that activates a color gene pathway that is already present in the mother, but not visible. Colors are typically reds, purples, blues. There is a rare South American type that is pastel yellow.
3- The endosperm is a triploid layer with two gene sets from the mother, and one from the father. It is also a xenia layer. Colors are typically white, yellow, orange.
4- Sap color is typically colorless, but purple variants exist. When present, they stain all other layers in the kernel often obscuring any other kernel coloration. Maternal only. No xenia effect.
I've been working with corn for several years and have most of this down pretty good but #2 in the quote filled a gap for me. I want my corn to be variable in color,
cob by cob, but not on the same cob. Finally I've come across an explanation of aleurone color inheritance. Colorless/transparent being recessive is perfect for my goals and now I know I don't have to discard an entire ear because of a few off-color kernels.