If you access the configuration of the Windows screen properties ("clicking" with the right mouse button on the desktop, or through the Control Panel), you will see that you have the option to set a theme for the system in which it predominates the black color Well, with Office Black you can now incorporate that same aesthetic to your favorite browser: Mozilla Firefox.
Office Black is an extension for Mozilla Firefox that allows you to easily customize the appearance of the popular browser, leaving it with the aesthetics of Office black (Luna Royale Black). The result is an elegant skin that includes two subskins: one lighter and one darker (the latter is more impressive.
Office Black is free and its installation is very fast and simple.
You can free download Office Black 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.