code: def desaturate(color, percent):
      """Desaturate a color by decreasing its saturation by percent"""
      return adjust(color, 1, -percent)
  
file_path: pygal/pygal/colors.py
imports: from __future__ import division
label_desc: Use image node_id 11 for calling a global function with example usage: desaturate(color, percent) and returns: adjust