text: my sister is mexican-american too but she has natural blond hair and hazel-green eyes? my sister is beautiful with her natural blond hair and colored-eyes, but she looks really different from me.yes,we got the same parents.we are both mexican-american,what could explain my sister's different physical features. basic mendelian genetics.  mexico was invaded by spaniards, many of whom had familial ties to the north, england, france, etc.  these spaniards raped many native mexican women, some actually had the respect to marry natives, and some american cowboys since then have added to the gene pool.  therefore, there are recessive genes for blue eyes and blond hair in both of your parents.  ask your parents or grandparents if they know of any caucasians in your family tree.  i bet you'll be surprised.