code: @Override
      public Color getAtomColor(IAtom atom, Color defaultColor) {
          Color color = defaultColor;
          String symbol = atom.getSymbol();
          if (colorMap.containsKey(symbol)) {
              color = colorMap.get(symbol);
          }
          return color;
      }
docs: Returns the Rasmol color for the given atom's element, or
  defaults to the given color if no color is defined.
  
  @param atom         IAtom to get a color for
  @param defaultColor Color returned if this scheme does not define
  a color for the passed IAtom
  @return             the atom's color according to this coloring scheme.