I’d like to add a palette for TIC-80 to the available presets that are included with Aseprite.
theres a “save as preset option” when loading palettes, at least in beta there is, but im pretty sure its on retail too
if you cant find it, save the pallete as a .gpl and in the aseprite directory add to the palettes folder.
I don’t have an answer to your question per se, but check out lospec if you haven’t already! Its a good place to share palettes.