Alter your Mac's looks
Since the arrival of OS X well over a decade ago, Apple has had a tendency to lock down its operating system's visual appearance in order to ensure as much consistency for its users as possible.
By contrast, it was possible to customize the appearance of older versions of the OS to a far greater degree. Options for "reskinning" OS X have been few in number and have quickly fallen out of favor.
This is mostly because making major changes has become an increasingly complex matter, meaning it risks system instability. You might want a Mac to look like something from your favorite sci-fi film, but that's not such a joy when your computer becomes less reliable as a consequence.
- Check out our Mac help and support guides for more Mac tips and tricks
That's why previously popular programs such as ShapeShifter, which enabled you to make sweeping changes to the whole look of the desktop, were never even updated to Leopard (OS X 10.5), let alone El Capitan.
Nevertheless, Apple realizes you need at least a few easy customization options, if only to personalize your Mac a bit. Accordingly, you can change your Mac's desktop background and screensaver; it's also possible to make minor changes to various global appearance settings, including muting system-wide colors.
If you're really brave, or very experienced, and you don't mind messing about without a friendly interface to guide you, you could always try GeekTool. As the name implies, this utility is aimed at the more knowledgeable user and is meant for more than decorative ends, but it does enable you to create cool customizations.
8. Transparency
Desktops show through the menu bar. If your picture is detailed, this can make the menu bar hard to read. Go to the Accessibility pane, choose Display, then check Reduce Transparency. This removes transparency all over OS X.