The CEP (Color Enable Package) enables colour options for many objects that Maxis shipped in only one colour (e.g. the potty chair, the exercise machines, the photo booth); the CEP also enables colour options for a second part of the object, when Maxis offered only one recolourable part (e.g. the books of the bookcases, the amplifier for the guitar, the marble base and the exterior of the coffin).
Once the CEP is installed, you'll be able to create additional recolours for those objects, and use recolours created by other users.
The CEP has absolutely nothing to do with Body Shop content (clothing, skin, hair, accessories, etc.); it ONLY effects Maxis objects.