code: def graph_background(s):
  
      
  
      if s.background == None:
          s._ctx.background(None)
      else:
          s._ctx.background(s.background)  
  
      if s.depth:
          try:
              clr = colors.color(s.background).darker(0.2)
              p = s._ctx.rect(0, 0, s._ctx.WIDTH, s._ctx.HEIGHT, draw=False)
              colors.gradientfill(p, clr, clr.lighter(0.35))
              colors.shadow(dx=0, dy=0, blur=2, alpha=0.935, clr=s.background)
          except:
              pass
docs: Graph background color.