I've been converting the existing character sprites for RPG Maker 2003 into composite parts. Just a few for testing. "Composite" was a section in the database where you assign the roles for the character sheets you import. You set the type of material there.
You can then add a colormap which applies the color ramps to the character set, and every pure monochrome color (R, G, and B are all equal) gets map to one of 16 selected colors in the map. This method of setting color is the fastest and most accurate where LandTraveller instead used series of functions and only a single color.
The parent body setting then associates parts to a particular body shape. If you use similar body types, you can clear the parent and use none which allows this part to be used by any body type. For the RPG Maker 2003 character sprites, there's just male and female body types.
With this information, the engine can just generate a character on the fly. You can do many things, like allow the player to make their character, make equipped armor and acc. show up on the player, generate many unique NPCs on the fly, etc. There are two slots for optional acc. that show up on top of a composite character.
Of course, sometimes you want a simple single character sheet. The "Full Sprite" type just uses the source sprite as is, which is useful for monsters. Color maps can still be used for full sprites in case you want to palette swap monster sprites.
The system isn't live yet, but I'll have sample characters to show soon.