If you want a purple Steam Controller, you can load Valve's STL into your favorite slicer, 3D print a new shell, transplant the electronics, and you're done.
If you want a purple MacBook, could you do the same with those Apple PDFs?
> This repository contains CAD files for the external shell (surface topology) of Steam Controller and the Steam Controller Puck
Then Apple's lawyers come for your liver.
Edit: spolling, I have a fever.