An unintelligent solution for finding the optimum level of blue light filtering for your viewing comfort.
Firstly get the daemon going:
redshift &
If you don't like what you see reset the adjustment:
redshift -x
To set a color temperature use the -O variable.
Pick a credible value.
Redshift recommends that low temperatures, for nighttime computing, be in the 3000-4000K range and that daytime tempreatures be in the 5500K-6500K range.
For instance, at nighttime, try:
redshift -O 4500
If it's still a little bit bright for you then reduce the value in small increments but you need to refresh the filtering first.
So try:
redshift -x redshift -O 4200
If you've gone too far with the blue light filtering then go the other way:
redshift -x redshift -O 4300
After much experimentation you will hopefully find something to your pleasing.
At which point you can update the configuration file in /~/.config/redshift.conf
Input the values that you were comfortable with along with the other changes.
Enjoy reduced eyestrain and more pleasant computing.