redshift:tldr:f3960

The command "redshift -O ${temperature}" is related to a software tool called Redshift, which is used to adjust the color temperature of a computer screen based on the time of day.

In this command, "-O" is an option that is used to set the desired color temperature value. The "${temperature}" is a placeholder for the actual temperature value you want to set.

Color temperature is measured in Kelvin (K) and represents the color appearance of light emitted by a display. A lower color temperature makes the screen appear warmer with more red or yellow tones, while a higher color temperature makes the screen appear cooler with more blue tones.

By executing this command with a specific color temperature value, you can modify the display's color temperature according to your preference or as part of a scheduled plan to reduce blue light emission during the evening or night, which can promote better sleep.