def rgb_to_cmy(r, g=None, b=None):
if type(r) in [list,tuple]:<EOL><INDENT>r, g, b = r<EOL><DEDENT>return (<NUM_LIT:1>-r, <NUM_LIT:1>-g, <NUM_LIT:1>-b)<EOL>
Convert the color from RGB coordinates to CMY.

    Parameters:
      :r:
        The Red component value [0...1]
      :g:
        The Green component value [0...1]
      :b:
        The Blue component value [0...1]

    Returns:
      The color as an (c, m, y) tuple in the range:
      c[0...1],
      m[0...1],
      y[0...1]

    >>> rgb_to_cmy(1, 0.5, 0)
    (0, 0.5, 1)