To the extent that the greenhouses are a significant source of light pollution, and every once in a while (faulty coverings, or for a holiday) the sky will be b

To the extent that the greenhouses are a significant source of light pollution, and every once in a while (faulty coverings, or for a holiday) the sky will be bright purple[1,2] [1]: https://www.reddit.com/r/Netherlands/comments/10mc6ah/can_anyone_tell_me_why_the_sky_is_purple_at_5_in/ https://www.reddit.com/r/Netherlands/comments/10mc6ah/can_an... [2]: https://www.reddit.com/r/Rotterdam/comments/ylmcgy/bright_purple_sky_in_rotterdam_around_2am/ https://www.reddit.com/r/Rotterdam/comments/ylmcgy/bright_pu...