One of the things I liked with MacOS was night mode in the evenings. This is where it shifts the colour temperature of the display to a warmer (more red) colour temperature.
Redshift is the package for Ubuntu that does this.
sudo apt install -y redshift-gtk
redshift-gtk &
Once you have that running click on the icon that appears and select Autostart
in ~/config/resdhift.conf add something like this (it’s for Melbourne AU)
[redshift]
temp-day=6500
temp-night=3700
location-provider=manual
[manual]
lat=-37.8136
lon=144.9631
One shot color change:
redshift -O 3700
Reset to normal:
redshift -x
Find your latitude and longitude (to set sunrise and sunset) here:
https://www.latlong.net/
For configuration options check out the page
http://jonls.dk/redshift/