The oldest coloured molecules in the world

Rocks beneath the Sahara Desert have revealed the oldest coloured molecules ever discovered. 

The molecules are bright pink although their shades range from deep red to deep purple and they are said by Australian scientists to be fossilised chlorophyll.  The pigments came from shale which was ground down before an organic solvent passed through the resulting dust. The solvent leached out the molecules, which were created by cyanobacteria in the seas 1.1 billion years ago, making these the oldest form of pigmented colour that we know. You can read more about this exciting discovery on the BBC website. 

Of course discoveries lead onto more questions. One that I want to know the answer to:  does the fact that pink is so old mean that it is simply the easiest colour for living things to produce? Is that why so many of our flowering plants are pink? Answers on a postcard please!