• Question: Why do most things have colouring?

    Asked by anon-177598 to Urslaan, Helen, Becky on 17 Jun 2018.
    • Photo: Becky Thomas

      Becky Thomas answered on 17 Jun 2018:

      Great question!!! Colour helps with camouflage (helping some animals hide from their predators) and communication (which could be a warning that something is venomous, or a way to attract mates, or identification so they don’t waste their time interacting with the wrong species). Colour also helps with temperature regulation (darker colours warm up more quickly) and in understanding agression (like the way a cuttlefish can change colours when they are not happy).

    • Photo: Urslaan Chohan

      Urslaan Chohan answered on 18 Jun 2018:

      I’ll take a physics approach! Every colour that we see is light being bounced back from objects. So a book looks blue because blue light is entering your eye after it is reflected. So why only blue, and not green and orange, for example? Well, light is made up of lots of different colours mixed together – white light is a mixture of ALL colours (red, orange, yellow, green, blue, indigo, violet). So for something to be blue, it has to absorb all colours but blue, and reflect that into our eyes. And you now may ask, what makes red and yellow different? To answer this, we need to understand the concept of “wavelengths”. Different colours have different wavelengths (the length between the highest and lowest parts of a wave). So the “blue wavelength” is reflected from blue objects, whilst all other wavelengths are absorbed by an object. Applying this knowledge, everything has colouring because it reflects different wavelengths of light. In biology, the colouring is caused by arrangement of proteins in the skin and eyes, for example.

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