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.
- makes a palette of up to 36 colours out of selected images;
- converts RGB to CMYK;
- finds the name of the nearest known colour (according to Wikipedia);
- finds the nearest colour on the Pantone C scale.