[Someone1234]

It is a cool idea, but creating that would require you to put a color e-ink display over the normal display panel, which may cause it to look washed out/lose crispness.

I think it is technically possible, I'm just not sure many would accept the cost/functionality trade-offs. But I may be wrong.

[mynameisvlad]

I think the idea parent comment had is to use the rollable technology from the article so that it only overlays when not in use.