`+referredFontForTextStyle:` is a class method on `UIFont` where as `-imageWithRenderingMode:` is an instance method on `UIImage`. But I just realized I made a mistake with `[[UIImage class] respondsToSelector:@selector(imageWithRenderingMode:)]`. It should be `[[UIImage class] **instancesRespondToSelector**:@selector(imageWithRenderingMode:)]`.