F.lux is a Blue Light Filter.
I like their old-version, which is almost 10 years old and works fine on Windows7.
I've slightly modified its embedded-manifest#1 #2 to work well on Windows-10,
and I've extracted the required settings to a registry-file so there is no installation process by importing the settings-in.
F.lux between two color-themes on sunset #1 #2,
by default, the UI only allows the color-filter to go-down to 3400Kelvin,
but I edited the registry-file and re-applied it to set the
day-time theme to 3400Kelvin and night-time to 2400Kelvin,
I've put the different values in the registry file with some helpful comments...
There is a need to apply a Windows-registry modification to allow a screen-color to go lower than 3400Kelvin, I've already included the "patch" in the program registry-file (first time applying might require a reboot to allow changes).
My modified version: github.com/eladkarako/mods/tree/store/F.lux.
If you need to assign a different longitude/latitude visit https://stereopsis.com/map.html and enter your location, copy&paste the result to the program.
This program does not requires internet-access, I personally don't want it to look for updates or to be collecting any statistics, so I've blocked the following domain in my HOSTS file:
#-----------------------------F.lux 0.0.0.0 forum.stereopsis.com 0.0.0.0 www.stereopsis.com 0.0.0.0 stereopsis.com 0.0.0.0 update.stereopsis.com 0.0.0.0 fluxupdate.stereopsis.com 0.0.0.0 fluxupdate.justgetflux.com 0.0.0.0 justgetflux.com 0.0.0.0 forum.justgetflux.com 0.0.0.0 update.justgetflux.com 0.0.0.0 www.justgetflux.com
Here are some color-filter related graphics: