I have a Pocketbook Colour which uses E Ink Kaleido and it takes multiple refreshes to correctly display colours - there's 3 or 4 flashes on the coloured areas.

Go to about 3:57 on this video and watch the book covers flash on and off as they do multiple refreshes - easier at 0.25x but still visible in real time.

https://goodereader.com/blog/product/pocketbook-color-e-read...