Your radical ideas about Kirby's colour changing have already occurred to others.
When Kirby's first game, Kirby's Dream Land, was released in the United States, Nintendo of America felt that a game with a pink star would not sell well. Because Kirby's Dream Land was a release for the original greyscale Game Boy, a colour swap merely required a change to packaging and instruction manual artwork. On the Japanese packaging however, Kirby is healthy and pink the way god intended!
Kirby went on to be a big hit all over the globe. However, outside of Japan he was being sold as a white little puff, not his true pink self.
Supposedly Shigeru Miyamoto was not at all happy when he heard about the change that was made to Kirby, and demanded that he remain his true pink colour in the future. Now, Nintendo know better then to make Mr Miyamoto unhappy, and Kirby has been pink again ever since.
And all was right with the world...
So, if you’re ever wondering why Kirby looks like a ghost on the cover of Kirby’s Dream Land, it was because of one thing: stupid marketing.