I was hoping that it would be a way to read through the comics I bought on Humble Bundle, but the colors are so washed out that I still just read them on a computer screen.
I have no idea what the engineering challenges are with making color e-ink, but they must be enormous because I (and many others) would pay considerable money for good color on e-ink.
I'm not a fan of Kaleido, as you say the colours are underwhelming, and the RGB filter attenuates light so the contrast is noticeably worse than classic mono e-ink. Gallery is way more expensive and slower to refresh though, so pick your poison.