docs: def rgb(color,default=(0,0,0)):
      """ return rgb tuple for named color in rgb.txt or a hex color """
      c = color.lower()
      if c[0:1] == '#' and len(c)==7:
          r,g,b = c[1:3], c[3:5], c[5:]
          r,g,b = [int(n, 16) for n in (r, g, b)]
          return (r,g,b)
  
      if c.find(' ')>-1:    c = c.replace(' ','')
      if c.find('gray')>-1: c = c.replace('gray','grey')
      if c in x11_colors.keys():  return x11_colors[c]
      return default