Why Do Unexplained Bruise-like Marks Appear On My Legs, Sometimes Purple Or Green, Without Pain Or Injury?

hello I have signs of bruises and beatings in my leg area that didn t happen at all. When I touch it it doesn t hurt. Sometimes the marks disappear but appear in a different place in the normal area, sometimes purple or green in color as if I received a contusion and was hit back very much. I would like to know what it could be or is it just