Have dark Knees? Dark mid region (crotch area)?

To start off: when I was young, I fell and scrapped my knees badly, and it never went away after months of lotions and scrubbing. also, I have seemed to develop dark skin around my mid region. no bad reaction, it's just dark, and I hate it.

Well, I had it also in my underarms, and I saw a commercial for dove deodorant that can fix my underarm issue of being dark and rough. surprisingly, IT WORKED! so after that, I had an idea of trying it on my knees, and middle area. after a couple weeks of this, IT WORKED!