++- Selene                                                 ** Veronica

brightness -r = color ->                                   (@ brightness:r color +-
  color.                                                       (" color.
    round ((red +                                                  (# round ((/ 3) (+ red
            green +                                                                   green
            blue) / 3)                                                                blue)))
  ;                                                            )
_                                                          +
  color : rgb                                                  {rgb} color
;                                                          )
