Here's why:
* Hair color isn't determined by nationality: Red hair, like any hair color, is determined by genetics, not where someone is from. People of Mexican descent, or any other descent, can have red hair.
* The question implies a misunderstanding: The question seems to suggest that Mexicans can't have red hair, which is not true.
It's important to remember that people from any ethnicity can have different hair colors, and making assumptions about this can perpetuate harmful stereotypes.