commander>Color Adjust
   macro>
    comment>Merge the work layers together and raise the color layer to the top
    comment>First the Retinex layer
    >>> RetinexLayer = pdb.gimp_image_get_layer_by_name(theImage, 'Retinex')
    >>> tempLayer = pdb.gimp_image_merge_down(theImage, RetinexLayer, EXPAND_AS_NECESSARY)

    comment>Then the Sharpen Layer
    >>> SharpenLayer = pdb.gimp_image_get_layer_by_name(theImage, 'Sharpen')
    >>> newLayer = pdb.gimp_image_merge_down(theImage, SharpenLayer, EXPAND_AS_NECESSARY)
    >>> newLayer.name = 'Contrast'
    comment>Desaturate the resultant layer
    >>> pdb.gimp_desaturate_full(newLayer, DESATURATE_LUMINOSITY)

   comment>Move the Color Layer to the top of the stack, name it ColorBase, set opacity to 80%
    >>> ColorLayer = pdb.gimp_image_get_layer_by_name(theImage, 'ColorLayer')
    >>> ColorLayer.name = 'ColorBase'
    >>> pdb.gimp_image_raise_item_to_top(theImage, ColorLayer)
    >>> ColorLayer.opacity = 80.0

    comment>Copy the Color Layer, call it ColorAdd, set opacity to 20%.  Adjust by hand as needed.
    >>> ColorAdd = pdb.gimp_layer_copy(ColorLayer, FALSE)
    >>> theImage.add_layer(ColorAdd, 0)
    >>> ColorAdd.name = 'ColorAdd'
    >>> ColorAdd.opacity = 20.0

