I'm on an iPhone 4 and my lock screen background isn't translucent when typing in my pass code. I assumed this was just because I was on an old phone and that it was just a feature for newer models. Then, tonight, my friend who also has an iphone 4 unlocked his phone and I noticed his keypad was translucent when typing in his pass code. What setting am I missing? (To clarify, we both had the same wallpaper [the multicoloured triangles wallpaper new with ios7] and we both locked our phones. On swiping to unlock, my keypad showed up as a dusky pink whilst his showed up translucent based on the colour behind each number).