Skyglow is two problems that look like one. Sodium lamps put an orange tint into the shadows, LEDs add green, and both raise the black point so the sky sits on a grey floor instead of black. Copper Wash is the reference correction, and it is a black-point and shadow-tint job rather than a saturation one: a blue shadow split against the sodium cast, with the black point set deep where the glow lives.
Floor entries do the level work. Lumen Wash takes the black point deep and cuts the curve toe. Vapour Cast adds a second floor drop through shadow luminance. Glow Floor rolls the highlights off so a streetlight in frame does not clip after the contrast move. Vapour Glow is the furthest from default on every visible parameter, and it still cannot recover a star the glow never let the sensor record.
Cast entries do the colour work. Suburb Sky neutralises with a blue-cyan shadow split, the complement of sodium orange. Sky Cast takes the green band down, which is the LED half. Amber Wash cools the white balance off the warm point a sodium sky sets. Bloom Edge darkens the glow itself by pulling orange and yellow luminance rather than draining colour. Field entries then give what survived somewhere to go: Sodium Wash raises the whites a little, Lamp Cast lifts texture and clarity, Street Glow is the lightest touch, for the edge of a small town rather than the middle of one.
Apply, then check the histogram. The left edge should sit at black with nothing stacked against it.
