Is there any way to incentivise the uptake of ChromaWallet amongst people running bitcoin nodes, and/or is there any chance support for it could be incorporated into bitcoin core?
I saw the code on the git, maybe the first step would be to re-write in c++. then figure a way to graft it.
There is absolutely no need to incorporate it into Bitcoin Core.
FYI first two implementations were actually in C++ (the first one was a proof-of-concept which modified Bitcoin Core (bitcoind), the second one was Armory-based).
It would take just a couple of days to add a color kernel to Bitcoin Core, but what's the point? How are you going to use it?