It's not nova launcher. Its the way the panel of the screen for Z1 is.
To test it well, using your Tapatalk to test. Set the theme to a dark one. Then come to a thread and start scrolling.
You'll notice that texts get more white when a bright picture is included in what you scroll, if you go past it, white text go back dull.
Its more like a dynamic thing but it sucks.
It just proves how poor the quality of the lcd is coupled with the viewing angle.
Sent from my C6903 using Tapatalk
Current: OnePlus One
Retired:Nokia N70, Nokia N91, Nokia E71, Nokia E90, Nokia N97, Nokia N900, iPhone 3GS, iPhone 4, HTC Sensation XE, Samsung GNEX, iPhone 4S, Samsung Galaxy S3, HTC One X, Nexus 4, HTC OneM7, Sony Xperia Z, Sony Xperia Z1, Samsung Galaxy Note 3.