When you go to the "Edit colors" option in the icon editor, it's pretty barebones. You are forced to edit colors via RGB values. There should be options to set colors to other colours that exist on the palette without having to manually entire their RGB value, as well as an option to just input a hex code. It sounds minor I know, but it would seriously make life easier for me and likely others.

(semi related but most of the palette-file related functions seem to not work properly.)