CommentStreams:A58857126fab0c90be9ebfe18bc7fc2e
From The Lost Media Wiki
Based on the hard evidence (The source code) I can see the mention of the pink version maybe being only a place holder in the code. I don't know, what that code says there, but maybe it's written to specify version differences, as all the other versions were released as a pair. Maybe the Pink version was considered, but scrapped. I can't see Game freak thinking yet another two versions would sell that well.