No. When you have yellow submarine on your lock screen, and apply green ambiance, changing almost all system, this yellow submarine don't suit to the system. Of course, as I said it is not problem to change it, and this function isn't really necessary, but with it, theme will be more consistent. In my opinion this is quite good idea, but I understand, that this is Ancelad project. I said only about Ancelad's reaction. There is a big difference between "sorry, I think that this option is not neccesssry" and laughing derisively.