title: AS3: Manually calculating RGB multipliers and offsets for brightness from -1 to 1
body: <p>How would you manually calculate RGB multipliers and offsets to adjust the brightness of a color so that an argument of -1 was all black and 1 was all white?</p>
  
  <p>If it's less than 1, it's easy. R, G, and B are just multiplied by (1 + brightness).</p>
  
  <p>But how would you calculate the offsets for brightness values greater than 0?</p>