Around six years back E-ink launched a 3-color screen to be used in signage. The tech is called Spectra, and it featured red, black, and white colors (but just those 3 colors, and no shades of black or red).
Depending on the features, the screen module costs wither $152 or $172. The lower price will get you just the screen, but for $20 extra you can get a kit that includes a frame and mounting hardware which will make it easy to attach a Raspberry Pi or another single board computer.
The screen itself has a resolution of 1304×984. This is low compared to most mobile devices but comparable to laptop screens. Its refresh rate is not, however. This screen tan take 16 seconds to refresh. That is a terrible lag time for a laptop's screen, but this screen was always intended for signage, a market where a 16 second delay is not a huge issue.