Very good and easy. But you should allow users to change the color of all text in design settings. admin can do this in controll panelappearance. But a normal user can not do this. That means, depending on what kind of color admin has set, again, the user must select a color background that matches the text color. Needless limitation I think. Going down this plugin something I think. Otherwise, it will not matter at Plugins, than again, certain themes are not compatible for change with this plugin!
My test here: