I've bought the Remarkable 2 and probably 10 Kindles over the past decade. I have never once been like, "You know what this eink device needs? Color!" I get that it might be a draw for some people but this just isn't appealing to me and I can't see the mass market use case for color besides color being neat.
Honest question, why did you buy 10 kindle devices in 10 years?
You can also sell them back to Amazon for a pretty good bonus when it’s time to upgrade. I think I sent back an old paperwhite and got $50 + 20% off my Scribe.
Right now I have an Oasis and a Scribe that I use about equally.
Reading is one of my bigger hobbies, I read around 100 books a year on Kindle.