Gpick supports exporting color palettes in formats gpl (Inkscape/Gimp), ase, mtl, and also import from formats gpl and ase.
In it still available a lot of different instruments, for example, you can even configure a css file.
It is possible that you will find something useful in this program.
Installation latest version into Linux Mint:
sudo apt-get install gpick
Remove from Linux Mint:
sudo apt-get remove gpick