To the point of your original post, unless your avatar is heavily doctored in Photoshop, you are strikingly beautiful. No doubt, your SO feels this way about you as well. Your pale skin is exotic and hightens that beauty. Skin pigmentation either on the basis of one's genetics or extent of sun exposure is not a specific feature of beauty.
Don't expend the energy to hate this other innocent woman--she's done nothing to you to deserve it. More importantly, hate does little other than harm you, the hater. Don't go down that road, it leads nowhere. Invest your effort, energy and attention to your relationship now, not arbitrarily hating an uninvolved former girlfriend.