The watch I really want is the Pebble Time 2 with a black-and-white screen.

The Pebble Time 2 is a huge step up from the Pebble 2 Duo in almost every conceivable way, but the contrast ratio on the latter is so much better that I still wear the P2D instead of the PT2, and just resign myself to deal with the lower resolution screen and inferior build quality.

Just don't use a color watch face?

the contrast ratio of a black-and-white e-ink screen is significantly better than the contrast ratio of a color e-eink screen when displaying black and white. It's a very noticeable difference between black-and-white vs dark-grey-on-light-grey. The P2D is much more comfortable to read indoors with the backlight off.

https://i.imgur.com/Z2Yrkl1.jpeg

Your reasoning is correct but Pebbles don't use E Ink screens. That's a specific technology made by a company by the same name.

agree 100%