How long does it take for burn marks to go away?

I had a tank top on and grease popped on my stomach. I iced it for about 5 minutes and after that it just stung. But now you can see the dark marks where the grease dripped on. It looks so weird and really stands out because of my complexion. I've been smoothing 100% coco butter on it everyday, hoping that it will lighten up soon