Natural multicolored hair is attributed to varying expression levels of genes responsible for pigment production. This genetic variability can lead to diverse hair colors, such as dark brown, blonde, and even reddish hues, often seen in individuals with mixed hair types. The Lyon hypothesis explains patchiness in hair color, suggesting that genetic factors can influence color changes over time. Some discussions point to the possibility of chimerism, where an individual possesses two distinct sets of DNA, potentially leading to unique hair color patterns. However, there is no known gene for green hair in humans; the phenomenon is primarily associated with specific cases in chimeras. An interesting note is that polar bears can appear green due to algae growing in their hollow hair follicles, but this does not apply to human hair.
