Before I even go into this, don't say some bullshit like, "use the search function, durr!". I've searched the forums for help on this but nothing relevant has shown up.

I've edited some ironsights I downloaded for the game to make them look a tad better, using paint. I renamed them to "semi" and "smg", and then I tried them out. Turns out whenever I aim down the sights, the whole screen (with the exception of my sights) turn white. The sights were the way I wanted them, but everything around it was fucked up :/

Can anybody tell me what I'm doing wrong here? I know this is a noob question, but save the trolling for later.