If you want a "messy" snake, try a zigzag or aztec.
Heterozygous means that the snake carries one dominant gene and one recessive gene for a particular trait. Most of the corn snake color and pattern mutations are seen in the snake if they are homozygous (carry 2 recessive genes) for the trait. A snake can also be homozygous for the dominant trait.
For example: A normal corn will have 2 dominant genes (homozygous) to produce the color black (often written as BB). It obtained 1 gene from it's mother and one from it's father.
A corn snake that is homozygous for the recessive "counterpart" to the gene that produces black (often written as bb) cannot produce that color and will be amelanistic (red albino). If these two snakes bred to each other, their babies will get a dominant gene (B) from one and a recessive gene (b) from the other, and will be heterozygous to produce amelanism (Bb). It will look normal in color (the one dominant gene is enough to produce the black color) but has the ability to have amel offspring if bred to another snake that carries at least one recessive (b) gene.