The standard P4 woman is also known as Posette. The P3 woman has different UV mapping but can use the same head morphs for characters. The P2 models, which ic what the Lo-Res figure seems to be, are different again. If you look at the free stuff in RDNA you'll find a couple of packages which allow a texture's skin-tone to be modified in Poser. While they're figure-specific MAT poses, the technique can be transferred, applying a pale-skinned texturemap over a base tint, to get some variation in figures. Once you have P5, you can also use the ambient color setting to lighten a texture.