onlyL rgb = Hls.fromHls (0, l, 0)
  where (h, l, s) = Hls.toHls rgb
onlyL rgb = Hls.fromHls (0, l, 0)
  where (h, l, s) = Hls.toHls rgb
onlyL rgb = Hls.fromHls (0, l, 0)
  where (h, l, s) = Hls.toHls rgb