I have both, a Boox Mira pro (monochrome only) as well as a Dasung Color EInk Monitor.

You actually get used to the monochrome thing. I've adjusted my syntax highlighting to use more italic, underline, bold etc so you get by without the semantic coloring.

The color eink is way better though. Only downside is that it has less contrast than the purely monochrome one. Color makes up for it nicely, though. Plus the refresh rate on the Dasung is way higher, so you can actually use a mouse without going insane trying to predict cursor movement.

Where the monochrome monitor was more of a secondary display primarily used for coding, I'm now using the Color EInk one as my main display.