Very few girl can pull off the red hair. If that is you in the picture then you are naturally beautiful and the hair color doesn't matter. The girl in the picture could dye her hair pink/blue/purple/all the color of the rainbow and still look good.
It all depends on the total picture. Red hair is sexy on a pale skin because of the contrast, but it will be less prominent on a dark skin. Also your cloths should match. Not all colours go well with red hair. So it requires a total change over, but if you do it correctly, you are dynamite