Ever wondered why you feel wide awake after a few hours of work in front of your monitor at night, and why you need a sleeping pill, even if your last cup of coffee or tea was in the morning.
Because your monitor is emitting a blue light, the same light that keeps you awake during the day.
Redshift was created for the pupose of making your monitor emit a reddish light at night, so working with a monitor at night will be less stressful for your brain, and you will be more prone to sleep well.
Look for the app in your PPM, it should be there : redshift is the basic package and redshift-gtk is a system-tray indicator icon.
The majority of people don't know anything about longitude and latitude, but redshift will be at its best if you have this information ready about where you live, be it in London, UK, or London, Ontario, Canada.
There is a website that will inform you on which longitude and latitude you live : http://www.findlatitudeandlongitude.com/
Neutral color is about 6500K, the color of a flash from your camera, and of your monitor. 3500K is a bit extreme, very reddish. You may want to have a color temperature more subtle, say 5000k. Your brain will be fooled into thinking it is dusk, and will prepare your body to feel asleep slowly, as is normal under normal conditions (no monitor in front of your eyes).
There are a few command lines useful to set color temperature, etc, but it is for expert only, since you need to know your way around a terminal.
If you need to know more, Googling redshift should help.
Just to let you know : redshift was inspired by f.lux, which is now available for Linux, as well as for Windows.
Redshift
geoclue
You may have to install geoclue. It is a location provider.
Otherwise you have to inform Redshift of your location manually, for exemple, in a terminal, for Paris, France : redshift -l 48.850258:2.351074
The model is : redshift -l LATITUDE:LONGITUDE
If the gui for Redshift does work in your Puppy, great! Or you have an alternative : using your terminal emulator.
Try : "redshift -O 3500"
3500 is Kelvin. Try 4000 K also.
In a Puppy, you don't have to use sudo in a terminal, but you may have to start with sudo in other OS for administrative rights.
Otherwise you have to inform Redshift of your location manually, for exemple, in a terminal, for Paris, France : redshift -l 48.850258:2.351074
The model is : redshift -l LATITUDE:LONGITUDE
If the gui for Redshift does work in your Puppy, great! Or you have an alternative : using your terminal emulator.
Try : "redshift -O 3500"
3500 is Kelvin. Try 4000 K also.
In a Puppy, you don't have to use sudo in a terminal, but you may have to start with sudo in other OS for administrative rights.