Dark spots on forehead, chest, neck (Photo)

I have had these dark spots on my chest, neck and forehead since I was younger. I believe they're birthmarks, but not entirely sure. They look similar to cafe-au-lait spots and are very splotchy. I also have something similar on my forehead but not sure if it’s related. Whenever I have extensive sun exposure, it’s usually the outer rims of my forehead that get darker. The spots on my forehead also have a weird leathery texture. Is there any way to remove this and to clear them?