Magical colour-changing Nicca?

[catskin.livejournal.com]

So, in my efforts to rid myself of the taint of the Merry books, I've been selling them online. Someone just bought a couple off me (ha! Suckers!) and as I was packaging them up, I flicked through for old times' sake and noticed something.

Nicca starts out as purple and lilac, like an easter egg apparently.

And then at some point he changes colour to chocolate brown and earthy shades.

So ... wtf? is my question.