改变tabBarItem颜色

[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
                                                       [UIColor blackColor], NSForegroundColorAttributeName,
                                                       nil] forState:UIControlStateNormal];

UIColor *titleHighlightedColor = [UIColor colorWithR:52 g:168 b:132 a:1];

[[UITabBarItem appearance] setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
                                                       titleHighlightedColor, NSForegroundColorAttributeName,
                                                       nil] forState:UIControlStateSelected];

[_secondVC.tabBarItem setImage:[[UIImage imageNamed:@"dianpu"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

[_secondVC.tabBarItem setSelectedImage:[[UIImage imageNamed:@"dianpu02"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];