Any painter knows that when they mix all the colours of this world the result is the colour of earth. Scarlet, amber, navy, maroon, tangerine, lime, chalk grind into one irrefutable brown. Brown is the great leveller, the pot at the end of the rainbow. Australian August autumn leaves. Are there other colours in the universe? Are there solar systems with several primary colours, or only one, unrepresented on our earthly spectrum? Would we see them if they were? Words would be needed to define what the light does. And are such thoughts mere daydreams of a resident of Earth?