• Question: how does everything natural get a colour (eg. grass is green)?

    Asked by Ellie 7246 to Alex, Ali, Kerry, Philip, Theo on 14 Nov 2014.
    • Photo: Alex Pool

      Alex Pool answered on 14 Nov 2014:

      Colour comes from light hitting a surface and some of the light being absorbed and some being reflected. So the colour we see is the light that bounces off and isn’t absorbed.

      White light is made up of a rainbow of colours – so if you put a prism in front of a beam of light you’ll see it create a rainbow.

      Hope that makes sense.

      Alex

    • Photo: Philip Ratcliffe

      Philip Ratcliffe answered on 14 Nov 2014:

      The colour of an object is determined by which part of the spectrum it reflects. The Sun’s light contains all colours and then, say, a blade of grass will absorb everything except green. Different chemical elements and molecules are associated with different colours and so it depends what the substance you are looking at contains. The colours that living organisms have is often a result of evolution: either they learnt to camouflage themselves or, like many flowers, grew bright colours to attract bees to help with pollination and so on.

    • Photo: Alison Thomson

      Alison Thomson answered on 17 Nov 2014:

      What Alex and Philip said! In addition to the light hitting the surface, the reason grass is green is because it is full of chlorophyll, which is a green substance. My hair is brown because it is full of a brown pigment., the same can be said for flowers – they have a specific pigment called anthocyanin which gives them their specific colour. Ultimately, it’s the chemical composition of something that determines it’s colour, and of course, the way the light bounces off it!

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