This is the same as MPMediaPickerController customize the colors of the labels and icons
.... in the app delegate :
[[UIView appearance] setTintColor:[UIColor blueColor]];
the command sets the colour tone for tab bars, toolbars, etc everything with a sillohouette icon.... Your tab bar seems seems to be translucent over a dark window background .... I use mpmediapickercontroller too in my app and I get an all white background with the default setting since moving to IOS 7. I believe it is your windows.backgroundcolor mine is set to white.