// Set the return key and keyboard appearance of the search bar
        for (UIView *searchBarSubview in [tableSearchBar subviews]) {
            if ([searchBarSubview conformsToProtocol:@protocol(UITextInputTraits)]) {
                @try {
                    [(UITextField *)searchBarSubview setReturnKeyType:UIReturnKeyDone];
                    [(UITextField *)searchBarSubview setKeyboardAppearance:UIKeyboardAppearanceAlert];
                }
                @catch (NSException * e) {

                    // ignore exception
                }
            }
        }

This will set the keyboard appearance of the UISearchBar text field to be black and see through.

Set Keyboard Appearance of UISearchBar

Objective C