text: /**
   * Created by grahamclapham on 30/09/2014.
   */
  ColourRamp  = function(){
  
  
  }
  
  ColourRamp.getColour = function(value){
  
      var r, g, b, ramp;
  
      ramp = 127;
      b = ramp;
  
      if(value > 0){
          g = ramp + parseInt(value*ramp);
          r = ramp;
      }else{
          r = ramp-parseInt(value*ramp);
          g = ramp;
      }
  
      return "rgba("+r+","+g+","+b+",1)"
  
  }