Personally I would pay more to have e-ink. Looking at it is like looking at paper! It is easier on the eyes, less drain on the battery. And most stuff software development wise, b&w is good enough.
There is a whole array of "notebook like" e-ink devices being created and released, but they mostly exist in, and target, the chinese and japanese market. Not the Western one. Remarkable is one of the exception and Kobo recently released one. Hopefully we will see more of it.
I personally think that the reason for this lack of device targeting the Western market is that the Kindle basically flooded the board and killed most of the use case. Sadly :(
However, they do have some nice devices like this color notebook with a pen and I guess that is what you were looking for: https://onyxboox.com/boox_nova3color
There is a competitor called DES Slurry
https://www.youtube.com/watch?v=FdAxyp7cj78
It has more colours, better resolution and better contrast... but it's refresh and update speeds are much slower than E-Ink... which hopefully will improve as time progresses
We need more competition in this space.
I've had my PocketBook Inkpad Color for over six months already.
Once e-ink technology advances enough to allow for these, it might compete with iPad, but until then the lag is severely limiting what the device can do. Reading books (one screen refresh a minute) is fine, but not much else.