def rgb_to_ryb(hue):
d = hue % <NUM_LIT:15><EOL>i = int(hue / <NUM_LIT:15>)<EOL>x0 = _RybWheel[i]<EOL>x1 = _RybWheel[i+<NUM_LIT:1>]<EOL>return x0 + (x1-x0) * d / <NUM_LIT:15><EOL>
Maps a hue on the RGB color wheel to Itten's RYB wheel.

    Parameters:
      :hue:
        The hue on the RGB color wheel [0...360]

    Returns:
      An approximation of the corresponding hue on Itten's RYB wheel.

    >>> rgb_to_ryb(15)
    26.0