As I once mentioned, I stole some code from Azote wallpaper manager to make a slightly larger color dictionary. It resulted in the azote-palettes GitHub repository. As the tool usability is limited to graphic designers, I see no point in adding it to AUR. However, if someone would like to take a closer look, I added the PKGBUILD file to the repo.
I didn’t expect to spend more time on this project, but the possibility to paste images is funny. For now it works on Wayland, and probably on Windows / Mac (not yet confirmed). X11 copy/paste feature coming soon (I hope). PKGBUILD updated.