Late 2015 4K intermittent display issue

[drewsof07]

Have a user with this weird issue on their 4K iMac with integrated graphics. She says it occurs randomly and persists for about 15 minutes across the screen, application agnostic. She finally sent me a photo of it in action (attached). Basically, hues of cyan, magenta, and yellow. I checked the serial and this machine just fell out of warranty. This is a business machine used 40hrs/wk. I have no hot swaps, so "just take it to the genius bar" is going to be a last resort. It doesn't seem like a hardware issue to me, but any advice would be appreciated.

Thx

Potato cam pic:

 

[curmudgeonette]

Suspect this is the Sierra 24 bit vs 30 bit graphics bug that affected so many 2016 MBPs. Is this computer running the latest macOS?

 

[drewsof07]

Suspect this is the Sierra 24 bit vs 30 bit graphics bug that affected so many 2016 MBPs. Is this computer running the latest macOS?

Yes, it appears to be running 10.12.3. The 4K panel is marketed as P3, would this be the culprit? A quick google didn't reveal any results on this particular issue. Trying MR now...

 

[curmudgeonette]

The 4K panel is marketed as P3, would this be the culprit?

Nope. It is just a software bug.

A quick google didn't reveal any results on this particular issue. Trying MR now...

Someone posted with this problem with one of the early Sierra betas. The thread didn't get many replies 'cause I guess the problem wasn't common. Discussion finally started when the 2016 MBPs showed this problem. It is unclear if Apple has fixed this or not.

One solution is to go back to El Capitan.