We see colours everywhere such as the mesmerizing colours of the flowers, the blue colour of the sea, the eye-catching green colour of the leaves, the 7 colours in the rainbow. Whenever I paint, I had this question in my mind, “What is the science behind this colourful nature masterpieces?” Well these remarkable and wide-ranging shades we see in usual things around us are all caused by pigments. Then what are pigments?
Pigments are biochemical compounds accountable for colour in a variety of existing things. Living things obtain their colour from natural pigments. They are found in plants, flowers, animals and of course, they are in our body too.
There are mainly 2 types of pigments;-
- Organic Pigments
- Inorganic pigments
Organic Pigments: Organic pigment are naturally made pigment. Naturally occurring pigments such as ochre and iron oxides have been used as colours since ancient times. Archaeologists have discovered evidences that early humans used paint for artistic reasons such as body decoration. Pigments and paint grinding tools believed to be between 350,000 and 400,000 years old have been found in the cave located in the Twin Rivers, Lusaka, Zambia. The discovery of a 100,000-year-old "paint workshop" in the Blombos Cave, in South Africa - complete with innumerable shades of ochre, bones, charcoal, grinding-stones and hammer-stones, abalone shell containers and mixing vessels, but with no testimony of that period cave painting - hints that the pigments were being used for body painting and face painting, rather than cave art.
Everything that happens in nature including the colours, are there for a purpose. For example, in nature, chameleons have the skill to change their body’s colour, not for attention but instead to hide from their predator. Here, the creature uses the colour to increase its chances of living.
Shades of green like olive green, lemon green etc. are found in nature are mostly due to plants. A pigment called chlorophyll gives leaves and flora their green colour. But as spring develops to autumn, the chlorophyll in the leaves deteriorate. Slowly, the green colour disappears and is substituted by the oranges and reds of another pigment called carotenoids.
Carotenoids also tetraterpenoids, one of the most common group of pigments, are also responsible for the wonderful rosy pink colour flamingos and salmon.
Inorganic Pigments: Pigments can be synthesized too. Inorganic pigments are mostly used today as they are stronger and lasts more than natural ones. Synthetic organic pigments are derived from coal tars and other petrochemicals. Inorganic pigments are made by quite simple chemical reactions or are found naturally as earths.
There are 2 types of inorganic pigments based on their elemental composition:-
- Metal based pigments (Inorganic)
These pigments are made from metals like Cadmium, Chromium, Cobalt, Copper, Iron oxide, Lead, Manganese, Mercury, Titanium, Zinc, and Aluminium.
- Other Inorganic pigments
These types of pigments are inorganic pigments of natural and synthesized origin like
Carbon, Clay earth, Ultramarine.
We can make different secondary colours by mixing the primary colours which are red, yellow and blue.
Which colour do you get when you mix the 2 primary colours, red and blue equally? Yes, you get purple, one of the colours which is hard for the human naked eye to differentiate. The word ‘purple’ comes from the word ‘purpura ’that describes a marine snail from which the original purple colour (Tyrian purple) dye was derived.
Which shade do you get when you mix yellow and blue? You get the vibrant colour which is also the colour of the leaves, Green!! Green is the colour of one of the most precious gems, emerald. The word green derives from the Middle English and Old English word “grene”, which, like the German word “grün”, has the same origin as the words grass and grow.
When you mix yellow and red, you get a secondary colour called orange. This vivacious colour is seen when spring unfolds to autumn. Colours, varying from a marginally orange yellow to an intense orange red, basically called saffron, are closely linked with Hinduism and Buddhism, and are usually worn by monks and holy men across Asia.