I would like a different background color when the user selects a tab bar item than when it is unselected.
Please refer below URL's.
Changing Tint / Background color of UITabBar
How To Change Tab bar color in Xcode
hope this will help you..
try this to change tabbar item color but it only work in ios5.
if ([UITabBar instancesRespondToSelector:@selector(setSelectedImageTintColor:)])
{
[tabBarController.tabBar setSelectedImageTintColor:[UIColor redColor]];
}