The Colour Purple
If you look at the bottom of Cadbury's website in the footer of the page, you find the following text:
..., and the colour purple are Cadbury Group trade marks in Australia.
Apparently Cadbury believes they can trade mark a colour, and according to a story on the radio they've been sending out cease and desist letters to other small chocolate makers in Australia.
It turns out that even though they are claiming it as a trade mark, they only have a pending application. The details can be found by going to here, choose "enter as guest", and enter "902086" into the search box at the bottom (it doesn't seem like you can bookmark a particular application).
It seems that the application has been pending since February 2002, and was deferred at the applicant's request 5 months later. So it seems weird that they've started trying to assert it now. The 17 categories the application mentions include soaps and perfumes, jewellery, kitchen utensils, clothing and leathergoods (it also includes classes that you'd expect a chocolate company to claim).
It seems like a clear abuse of the trade mark system, and I'm surprised it isn't getting more news coverage.