This solution requires F.lux to be installed (I assume it's at
Create a text file (let's call it
flux-day-color) and put it in
usr is under "Macintosh HD" and may be hidden).
if [[ ! -z "$1" && "$1" -ge 2700 && "$1" -le 6500 ]]; then
defaults write org.herf.Flux dayColorTemp -int "$1"
echo "provide a temperature between 2700 and 6500 (rounded to nearest 100)"
In Terminal, run
chmod 755 /usr/local/bin/flux-day-color
Now you can run
flux-day-color 2700 in Terminal (or in another script) to change the day temperature. Note that the script restarts F.lux so you may see the display jump to 6500 K for a split second before applying your requested temperature.
It's also possible to schedule this to run at predefined intervals, but that's beyond the scope of this answer (and the question).
If you'd rather have a launchable app that can toggle between 2 temperatures,
Open Terminal and run these commands:
mkdir -p flux-day-toggle.app/Contents/MacOS
cat <<END > flux-day-toggle
Now you'll see a greater than sign. Paste this:
cur_val=`defaults read $DOMAIN $KEY_NAME 2>/dev/null`
if [[ -z "$cur_val" || "$cur_val" -eq "$HIGH" ]]; then
defaults write $DOMAIN $KEY_NAME -int $new_val
Wait for the prompt to appear, meaning the file was written.
Now the finishing touch:
chmod 755 flux-day-toggle
Now you can launch the new app. You can customize the LOW and HIGH settings to your liking.