Actually the whole theme is plain black. It is the Firefox 57 that changed the color on the lower part on the way it is designed. Others have mentioned this, too. Until Firefox 57 changes the way that part of the browser is designed, I can't do anything about it. Thanks for the 4 stars, anyway.
Thanks, EK. I miss a lot of the add ons I had before the 57 update. I haven't installed it on my desktop yet because 57 doeesn't have a way for me to preview a theme so until that happens, I will put it off as long as I can. Glad you like the black!
La simpleza y utilidad son casi sinonimos de genialidad, el minimalismo suele ser lo mas eficiente. Uno suele concentrarse en el conteido de las paginas que se esta visitado asi que u tema como este, creo yo, debe ser lo mejor para la tarea