Hopefully you mean that they are complimenting about red hair. Maybe because it's not as common as the other hair colors, so you stand out. I love red hair, my Mom is a redhead, and we have a few our family.
"Redheads" are only about 10% of the population. I was one when I was much younger. (Its gray now.) But I have always been fascinated by the whole appearance of red-haired girls--probably because their physical coloring in general (appearance) tends to be so unique.