Amazon has a bit of a grip on the e-reader industry. Much like Kleenex did with tissues, Kindle has become so synonymous with e-readers that it’s easy to forget there are other brands out there. Which is a bit of a shame, because it’s only from companies like Rakuten that you’ll find more experimental features like colored e-ink.

Rakuten’s latest e-readers, the Kobo Libra Colour and Kobo Clara Colour, aren’t the first color e-readers to hit the market. But since Rakuten is the Pepsi to Amazon’s Coca-Cola, they offer a familiar, Kindle-like form factor and a robust e-book ecosystem. They’re a great example of the kind of innovation a second-place manufacturer needs to make to stand out, but their niche use cases and multiple drawbacks illustrate why Amazon hasn’t yet followed suit.

There’s more to the Kobo Libra and Clara Colour than just their colour displays, but the displays are certainly the standout difference here, especially since Kobo is the largest e-reader company to adopt a colour display to date. For most devices, buying the colour version always seemed like a no-brainer. A colour TV can display more lifelike images, and a colour Game Boy can give the player clearer images. For e-readers, the transition to colour isn’t so simple.

That’s because books are largely black and white anyway. Dune reads the same on paper as it does on a Kindle and a computer screen, aside from the individual quirks of each medium. You don’t lose any information by going black and white, except maybe on the cover. That’s why Rakuten is focusing on two use cases in marketing the Kobo Libra and Clara Colour: comics and note-taking.