Does a black screen save battery on a macbook? I've seen some similar questions about iPhone on this site, but none of them focus on macbook, so here comes this one.

The picture below is a screenshot of my current desktop, with menu bar and dock hidden, as well as grey scale turned on. 



Can some pattern (black specifically) save enough energy on a macbook that you’d get more than 5 minutes runtime in a full battery to discharge cycle?
No. No battery will be saved regardless of what color your screen is. This only applies when the screen is OLED, like in the Apple Watch. 

You can save battery by lowering the screen brightness, though.