title: how to set RGB colors in Pymol
body: <p>Can I ask if Pymol allows users to set atom color by user defined value ?
  for example, I want to color all atoms by their biochemical features, the feather is considered to be RGB value, say [R G B] is equals to [feature1 feature2 feature3], how can I 
  do this in Pymol ?</p>
  
  <p>In addtion, if I already color the atoms, can I get the color value ? I tried to use cmd.getcolor(), but the value it returns is not recognized as RGB color, is there any other 
  function in Pymol I can call to get atom color ? </p>