The reason I know about this pretty cool feature is my cat. He accidentally jumped on my keyboard one day and activated this command, so I had to spend ages looking for what it was. But now I know it’s actually pretty awesome. And it’s extremely simple to do.
The one command you need for this is CTRL + COMMAND + ALT + 8. This will give your screen the above effect. To turn it back to normal, just repeat the same key combination.
A part from looking completely awesome, I find text is much easier to read using this setting. Not that you would want your screen like that all the time, but I reckon it puts less strain on the eyes than the colour scheme of a normal screen. The setting is included in OS X as an accessibility feature for people with certain vision conditions.
For more helpful tips, check out our full collection of tutorials by visiting our How-To category!