Color E-ink Screen, 199 Euros

I see a lot of those, but imo, 6 inches is insanely small and is suboptimal for most of my uses (mostly reading). I can barely get some textbooks to show up correctly with a 8inches display.

I assume it's feasible if you only read epubs, but what would a color 6in ereader add of value?

Disclaimer: I love the techand wish this was >6in

Does anybody know how to interpret “users can adjust color settings of each specific book, easily changing parameters such as contrast, brightness, gamma correction, and saturation.”?

The cynic in me reads it as “users must tweak settings for each book”, but if so, why would that be?

If not, why would a reader have per-book settings?