Joined: June 2007
Given the way color vision works, blue-green would almost be required to evolve before grue-breen. The eye works by filtering light through different colored pigments, much in the same way digital cameras work - consumer grade cameras have built in filters, like our eyes, scientific grade cameras usually place filters in front of the entire sensor, but still work in a similar manner.
Too add in a timer that swaps around colors at a certain date requires adding on to the existing color vision mechanism. This means that, in order to spread through the population, there needs to be some reason why grue-breen is selected over blue-green. The more complicated something is, the easier it is to break, so this seems unlikely.
To rebut creationism you pretty much have to be a biologist, chemist, geologist, philosopher, lawyer and historian all rolled into one. While to advocate creationism, you just have to be an idiot. -- tommorris