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<b>Did you know that colour is only in your head ?</b><br>
<b>-</b> Surfaces reflect, absorb, transmit or emit electromagnetic radiation, the cones in a retina react to certain wavelengths of radiation, 
which we call visible radiation or the visible spectrum. Because we have three types of cones sensitive to different but overlapping wavelengths 
our brain is able to produce for us the sensation of colour as a means of distinguishing between objects with differing spectral properties.<br>
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