Yeah, this is the huge drawback. Also AFAIK there are better screens already out there with >1000 colours, e.g. Boox Nova C https://medium.com/boox-content-hub/e-ink-kaleido-vs-new-kal...
There is a single competitor DES color, but they seem to be in presale since years. https://www.youtube.com/watch?v=ckFJar6NC0o