Just thought id post it because its something I recently worked on for zdoom, that game has some limited palette issues also given that it was optimized only for the stuff they had in it. So there were alot of colors that had large ranges given to them while maybe it could have been done with fewer.
I cooked up a new palette for zdoom which works by having all the original textures and sprites converted to .png format (as a spare resource file loaded after the primary one) so that their colors would remap using the game engine, and it works pretty well.
The thing is, while this palette may not be entirely ideal for UFO Defense or TFTD, with some tweaking it could easily do what the game/style needs it to do while offering color availability that just isnt present in either game. Like for example the pinkish skin tones can become the soft lavender that is frequently seen in TFTD.
One way I do it is taking a color range - say the Grays or the Skin Tones, and every other color down the range scintillates between saturated and unsaturated. Not a big difference but its "just enough" that it can provide a bridge or make do.
They gray tones especially, while some people like seeing flat gray ranges in my experience actual gray isnt a realistic color to see, usually you see off-white yellowish ivories, faded taupe and bluish slate. So it actually cycles between those.
The darker colors are also hard to make out or notice to the human eye anyway, so alot of colors that fade into darkness, they fade into like one of 3 applicable colors so a bunch of extra dark tones are truncated to make room for more hues.
Im probably not going to fork much work into adapting it because palette adaptability seems like its in its infancy for OXC and im unlikely to get into any heavy lifting with mod work.
This .png file has the palette in it, and I dont mind if somebody else takes it and modifies it or gets inspired by it.
