@rempelj doesn't want to implement "body part" items until a system is in place to automatically match the item to your skin color.
You mean the "Fill with color" feature in MSPaint? That's been there for decades.
None of the skins are a solid color. They are all textured in some way.
There are a couple blocking changes that would be required before body part items can be implemented.
First there'd need to be a special flag in the database to identify which items are skins. Then all of those skins would need an additional uploaded file for a texture pattern. For example if you have the goldfish skin, there would be a texture of that goldfish pattern which fills the entire character area. Body part items would need to be created with a special color (like magenta) that gets replaced with the appropriate skin texture at render time.