Even basic colour support (like 3 colours in addition to black, no grayscale) with a 1Hz refresh rate might be enough for me... And I would have expected us to

Even basic colour support (like 3 colours in addition to black, no grayscale) with a 1Hz refresh rate might be enough for me... And I would have expected us to have them by now, considering how colour e-paper has passed the prototype stage and is now widely used in supermarkets for labels ??