I have recently purchased an Inky Frame 4.0" and an Inky Frame 5.7". Both suffer from “green failing”.
Every few days I have to re-seat the display flat cable in order to get the color green to work again. But after a while, the screen looks yellow and green is gone. Redraw doesn’t fix this, but removing and re-inserting the flat cable before redrawing does.
The cables are now so perfectly and carefully repeatedly inserted, the cable insertion service is worth half the Inky Frame. This, and the odds of two Inky Frames failing with the same color, make me wonder if there’s a known problem with these devices.