When comparing Redshift GUI vs F.lux, the Slant community recommends F.lux for most people. In the question“What are the best apps to reduce Eyestrain?” F.lux is ranked 1st while Redshift GUI is ranked 3rd. The most important reason people chose F.lux is:
Helps provide better sleep for more energy during the day.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Can help sleep better
Helps provide better sleep for more energy during the day.
Pro Eases eye strain
Decreases color temperature at night, changing the normally fluorescent blue of an LCD monitor to a soft orange. Much easier on the eyes, especially in a low-light environment.
Pro Subtle transition
The transition from daytime to nighttime color modes takes an hour by default and will detect your current timezone, meaning that it will happen in the background at sunset, often without you noticing.
Cons
Con Discontinued
The project seems to be no longer developed. Last version, 0.2.4, released in August 2014, can be still downloaded from GitHub.
Con Takes a while to get used to
After installing F.lux, the screen will look a lot more yellow. This takes about a week to fully get used to. You can ease into it by setting the color temps higher than the recommended defaults.