ifying the Saturation) or colourising a whole
image (by modifying the Hue).</p><h2>Coding the HLS Model</h2><p>Normally Hue is expressed as an angle between 0-360 to describe the colour 
and a value between 0 and 1 (a percentage) to describe Hue and Saturation. I have 
missed out the conversion to an angle in this implementation so the Hue works as follows:</p><pre>
Hue   Colour 
 -1   Magenta 
  0   Red 
  1   Yellow 
  2   Green 
  3   Aqua 
  4   Blue 
  5   Magenta 
</pre><p>Here is the code to do a con