If you want to change the appearance of UISearchBar and its related elements then use below code.

-(void)changeSearchBarAppearance{

    [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setBackgroundColor:[UIColor whiteColor]];
    UITextField *searchField;
    NSUInteger numViews = [_searchBar.subviews count];
    for(int i = 0; i < numViews; i++) {
        if([[_searchBar.subviews objectAtIndex:i] isKindOfClass:[UITextField class]]) { //conform?
            searchField = [_searchBar.subviews objectAtIndex:i];
        }
    }
    if(!(searchField == nil)) {
        searchField.textColor = [UIColor whiteColor];
        [searchField setBackground: [UIImage imageNamed:@"yourImage"]];//just add here gray image which you display in quetion
        [searchField setBorderStyle:UITextBorderStyleNone];
    }

}

Happy Coding!!!