code: def get_line_color(self, increment=1):
          
  
          i = self.line_colors_index
  
          self.line_colors_index += increment
          if self.line_colors_index >= len(self.line_colors):
              self.line_colors_index = self.line_colors_index-len(self.line_colors)
              if self.line_colors_index >= len(self.line_colors): self.line_colors_index=0 # to be safe
  
          return self.line_colors[i]
docs: Returns the current color, then increments the color by what's specified