However, a Sim's hands are separate hands are not part of body skins, but are defined separately in the Sim's character file. Each image file is that Sim's entire body or head, including skin (there are 3 skin tones - light, medium and dark - and it is common for the same outfit to be made in all 3 tones) and hair.
Both are simple 256 color (8-bit) bitmap images, numbered to correspond with the mesh file which gives them the desired shape on the Sim. Skins in The Sims are comprised of two parts per Sim: a head and a body.
