The Palette files can be extended from 0-175 to 0-255 options.
This will require some fixes to the engine to really work but can be suitable for larger palette files used by scripting.
Some ideas from the community;
matte yellows that aren't faded
iirc there are good red and green gradients in the upper half (or lower in the tga), but not blue. Maybe add a group of 4 blues, not very outstanding, something you can use in medieval robes and clothes without being too striking
Need to review the current palette files for reference.
Some notes on colour names here; https://wiki.avlis.org/Dynamic_Dye_Color_Chart