Flexi Says: Of course human eyes do not come in multi-color, but they do come in many colors. How do eyes come in so many colors? That brings us to complex inheritance patterns, known as non-Mendelian inheritance. Many times inheritance is more complicated than the simple patterns observed by Mendel. Usually, traits are polygenic when there is wide variation in the trait. For example, there is a wide range of skin color across people. Skin color is also a polygenic trait, as are hair and eye color.