Customize about:newtab (please see point 3 below).So far I know a couple of addons to achieve that and a way to do without addons (as it seems a lot of them are disappearing day by day), here we go then: also, if you want, you can still juggle with CSS (see point 3 of original answer below). That said, if you're looking for something minimalistic there are also addons that work straight forward and provide just the very basic feature to only change the new tabs background to something dark, for example Dark New Tab There are also some addons that, despite background, lets you customize tiles on new tabs as well, I think you may like it and find the thing useful so I'll provide some worth a try imho: (As a last note here let me say Tabliss is like joining the features of New Tab Override, New Tab Wallpaper, Beauty Tab, New Tab Splash and Clock New Tab addons all togheter.) It lets you customize the new tabs background not only choosing for a color but also beautiful background images and add widgets (like showing the time for instance). This is a really nice one (I personally use and love it).
If this isn't enough, let me add this addon is develope by Mozilla itself. This imho is really THE DEFINITIVE ONE and A MUST HAVE! Not only it lets you deeply customize almost everything of Firefox GUI the way you like it (including new tabs background of course), it also lets you share the theme you made if you want. I think this may interest others as well.īy now there's a lot of cool and interesting addons that do the job in great way, let me mention some of my favorite in a brief list: