I've had my sliver iPhone 5S for 6 months and I keep having a issue where I get a blur when opening up apps. Depending on my wallpaper, it is black or white. I am taking it to apple, and I want them to replace it, but I also now hate the sliver color, and really want space gray. I have no upgrades right now. Can I request them to exchange my sliver phone for a gray one? I would be willing to pay and I also buy my phone unlocked at full price.