They are very faded compared to a normal screen. With no backlight and in direct natural light, the Kaleido screens look similar to a color newspaper or many comics. (Some comics use paper and printing that produces much more vibrant color though)

In artificial light a lot depends on the specifics of the environment. Trying one out in warmer light, somewhat indirectly (light overhead, screen partly vertical for reading) it was a little dark, and needed the backlight. It was a cool backlight, so the warm overhead light combined with it to counteract a bit of the shift toward blue. In the dark w/o external light, the cool backlight very much shifted color towards blue.

This is just what these displays are capable of. I guess, that also might be the reason, they took book covers from the 1940's. Vintage look is quite attractive, this way, but it would be worse with modern high-def imagery.

I wish they had not used vintage magazine covers for their illustration. By using old covers, I wasn't sure how much of the drabness was caused by the device and how much was attributable to the original image being drab.