code: protected int getColor(Node node)
  	{
  		if (!colors.containsKey(node))
  		{
  			// Absence of color is interpreted as white
  			return WHITE;
  		}
  		else
  		{
  			return colors.get(node);
  		}
  	}
docs: Gets color tag of the node
  @param node Node to get color tag
  @return color tag