@ecjb1969 Night shift default DOES NOT remove enough alerting light (it's over 4200K) at night. That was the flux-teams best guess in 2009 as it was seemingly all new to them. They now understand that it's just nowhere near enough. I strongly suggest you use the "more warm" setting, which is 2700K or really close. Apple doesn't care, it's a crappy interface with NO detail, and a horrible default.
The Apple developers can call the f.lux team, and have, but it was only to stop them from making f.lux for iOS. The apple devs don't want to help them, they want to make Apple look like innovative for a feature they were BEGGED to include. I'm very dissatisfied with apple's performance on this issue, and I hope it improves.
Sorry about that, what color lights do you have? Maybe you still have the boxes and can check? A warm white 2700K light is ideal at night, but I'm not sure what f.lux is set to for "recommended settings". If you could enlighten me because I don't think it's mentioned in the quick start guide.