What Is The Treatment For Black Marks In The Legs?

Hi...Ever since I was small I have had black marks on my legs. They are very black. Some are big and others are small. I have no idea where they originated from but I have noticed over the years that every time i get a cut or a bite or any kind of scar, it turns black and stays on my legs so you can imagine how spotty my legs look. I have tried all the fading creams and the applying of lemon and so on. I am totally hopeless and I have absolutely no self confidence when it comes to my legs. I do not wear short clothes at all but I want to. Is there anything I can do?