crazy rainbow screen on startup. New iMac with Sierra os

This is not the first time that we've seen strange graphic anomalies after upgrading the latest iMac's to Sierra.

Personally I'm not exactly sure what the problem is, but in the mean time it might help to send Apple some good feed back.

http://www.apple.com/feedback/imac.html

http://www.apple.com/feedback/macosx.html

Please read the warranty paperwork that came w/your computer.

You have 14 days from the date of purchase to return the computer w/no questions asked.

You have 90 days of FREE phone tech support on top of your standard 1 year warranty unless you also purchased AppleCare which gives you an additional 2 years of coverage plus FREE phone support.

Strongly suggest that you take FULL advantage of the above before it runs out.

Let Apple deal w/the problems & your concerns. It's what you paid them to do.

I have the nearly the same problem. No rainbow screen. But I get the same pixelated apple in red and green when starting up. I got my new iMac 21.5' last week and I get the same error every time I'm starting it :-(

OMG I was just in the phone with Appel support and they said this was rare and that she had never heaed of this. I could t post the pic because this forum kept saying it was to big. Have you spoken to apple yet? i have the iMac about 4 months old.