[SOLVED] Muddy images on Asus screen

The screen is connected to a MacBook air via USB-C. The contrast was bad, and certain information on the window bars were almost unreadable. First I thought that the issue had to do with the MacBook. 

However, the solution was in the actual ASUS screen.

I turned OFF HDI, strangely enough - that did the trick!

Solution: Turn off HDI.