When I had my E7 and did not have burn in, but I did have image retention which scared the crap out of me It took about a week for it to be completely gone and not visible, but it did go away. The bad thing was that for that entire week whatever I watched or played I could see that image. To the OP points, it was a yellow and specifically on Xbox One the Cuphead game tile when in the dashboard. I had my Xbox on the dashboard and got a phone call, I was away from the set for about 20-30 minutes and I was using the dark theme, so the back round was dark with that bright yellow Cuphead logo. While it was not permanent it does show that Yellow is tough on OLED or at least my 2017 model. I do also have to say I did not have this issue again as I was a bit more careful and the small temp IR I had after was only present for a very short time. I would still buy a OLED but know that you do have to be careful, especially with bright yellow/orange.