I recently had to buy a new TV so I picked up an Insignia 43″ 4K Roku TV on sale from Best Buy. I noticed right away that the screen had a serious problem. Any patch of black or near-black had hard blocky green sections mixed in, like it was calculating that the green was close enough to black to be equivalent. Thankfully I stumbled across a fix. But first, here’s an example:

Notice the ugly effect on the walls on the right hand side. It’s even more noticeable in motion because the green blocks move frequently.

I tried to adjust the color settings in the Advanced Picture Settings however all I was able to do was to darken the picture to make it less noticeable. Not ideal.

While I was trying to find anyone talking about it online, I stumbled across a post from Roku saying that you could access advanced video settings in an iPhone app. I played around with it and found something handy: changing just one of the white balance settings immediately fixes the green blocking problem. The picture looks so much better.

So here’s how to fix it:

  1. Download the Roku Mobile App on your phone and make sure you’re on the same network as the TV.
  2. Go to Expert Picture Settings in the app.
  3. Pause a video on your TV which shows the effect of the green blocking (so you’ll be able to confirm the results).
  4. Under the heading 11 Pt WB, click on the green/center column in the 5% row.
  5. Click on the minus button once, changing the value to -1. You’ll notice that the video immediately changes and the shadows are much more accurate.

Now your Insignia 43″ 4K Roku TV is fixed! Note that if you change the color options on the TV directly, you’ll need to go back into the app and make the change again to fix the issue.