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Scientists Discover the World's Oldest Colors (phys.org)
1.1 billion-year-old bright pink pigments extracted from rocks deep beneath the Sahara desert in Africa are the oldest colors on record. They were discovered by scientists from The Australian National University (ANU), with support from Geoscience Australia and researchers in the United States and Japan. Phys.Org reports: Dr. Nur Gueneli from ANU said the pigments taken from marine black shales of the Taoudeni Basin in Mauritania, West Africa, were more than half a billion years older than previous pigment discoveries. The fossils range from blood red to deep purple in their concentrated form, and bright pink when diluted. The researchers crushed the billion-year-old rocks to powder, before extracting and analyzing molecules of ancient organisms from them.
"The precise analysis of the ancient pigments confirmed that tiny cyanobacteria dominated the base of the food chain in the oceans a billion years ago, which helps to explain why animals did not exist at the time," Dr. Gueneli said. Senior lead researcher Associate Professor Jochen Brocks from ANU said that the emergence of large, active organisms was likely to have been restrained by a limited supply of larger food particles, such as algae. "Algae, although still microscopic, are a thousand times larger in volume than cyanobacteria, and are a much richer food source," said. The study has been published in the journal PNAS.
"The precise analysis of the ancient pigments confirmed that tiny cyanobacteria dominated the base of the food chain in the oceans a billion years ago, which helps to explain why animals did not exist at the time," Dr. Gueneli said. Senior lead researcher Associate Professor Jochen Brocks from ANU said that the emergence of large, active organisms was likely to have been restrained by a limited supply of larger food particles, such as algae. "Algae, although still microscopic, are a thousand times larger in volume than cyanobacteria, and are a much richer food source," said. The study has been published in the journal PNAS.
I think we can accept part of the linked article - that pigments have been identified in very old rocks.
However, the phys.org piece then seems to claim that this is somehow "pigmentation", inferring that this is an aesthetic feature of the life form at the time. There is no suggestion that these life forms had developed organs capable of what we recognise today as "sight".
The simple fact is that chemicals generate colours. Copper sulphate solution? It's a cyan-blue. Potassium Permanganate solution? Tha's purple. But copper sulphate isn't blue for aesthetic reasons, it's blue because of the way that light interacts with the molecular structure of the compound. It is a direct result of the physical properties of the compound in question.
Treating this as though it were somehow a remarkable discovery is complete nonsense. We know that chemical reactions - inorganic as well as organic - produce compounds of given colours and pigments. I can put chunks of metallic copper in to sulphuric acid and get blue copper sulphate, but that isn't some pigment created by a life form. That's just chemistry.
In other words, what this article is establishing is not some aesthetic pigment produced by an ancient life form. It is, instead, identifying a potential range of chemical processes that the life forms could have used as part of their metabolism. Well, having a metabolism is one of the identifiable features of "life". It doesn't imply that the "colours" that result come from anything beyond that basic chemistry.
Nothing to see here. Move along, move along.
Probably more correct to say "oldest rock color".
No, the oldest confirmed rock on Earth at 4.4 billion years old is a nice blue zircon.
However, the oldest "colour" in the Universe though is technically the Cosmic microwave background. Some of those photons used to be in the visible spectrum but are so old, dating from 300k years after the Big Bang, that the expansion of the universe stretched them into the microwave region. So, if anything, the oldest colour is what we now perceive as the black between the stars and galaxies.
I took it as a Calvin and Hobbes reference.