code: def get_colors(self, prefix, len_):
          
  
          def color(tupl):
              """Make a color css"""
              return ((
                  '%s.color-{0}, %s.color-{0} a:visited {{\n'
                  '  stroke: {1};\n'
                  '  fill: {1};\n'
                  '}}\n'
              ) % (prefix, prefix)).format(*tupl)
  
          def value_color(tupl):
              """Make a value color css"""
              return ((
                  '%s .text-overlay .color-{0} text {{\n'
                  '  fill: {1};\n'
                  '}}\n'
              ) % (prefix, )).format(*tupl)
  
          def ci_color(tupl):
              """Make a value color css"""
              if not tupl[1]:
                  return ''
              return (('%s .color-{0} .ci {{\n'
                       '  stroke: {1};\n'
                       '}}\n') % (prefix, )).format(*tupl)
  
          if len(self.colors) < len_:
              missing = len_ - len(self.colors)
              cycles = 1 + missing // len(self.colors)
              colors = []
              for i in range(0, cycles + 1):
                  for color_ in self.colors:
                      colors.append(darken(color_, 33 * i / cycles))
                      if len(colors) >= len_:
                          break
                  else:
                      continue
                  break
          else:
              colors = self.colors[:len_]
  
          # Auto compute foreground value color when color is missing
          value_colors = []
          for i in range(len_):
              if i < len(self.value_colors) and self.value_colors[i] is not None:
                  value_colors.append(self.value_colors[i])
              else:
                  value_colors.append(
                      'white' if is_foreground_light(colors[i]) else 'black'
                  )
  
          return '\n'.join(
              chain(
                  map(color, enumerate(colors)),
                  map(value_color, enumerate(value_colors)),
                  map(ci_color, enumerate(self.ci_colors))
              )
          )
docs: Get the css color list