I’m currently looking for a possibility to set the color temperature of the screen permanently. I already tried sct or gummy, but none of them had any kind of effect. sct is working on my work laptop having Ubuntu 20.04 installed, so I was a bit surprised that it had no effect on Manjaro.
Currently I use the night mode from settings which has the side effect, that it also activates the night theme. I disabled the plugin Night Theme Switcher as well, also had no effect.
I use Gummy on another arch-based distro & found it simple to manipulate, but I think its only for X11.
If you are using Manjaro Gnome (wayland, by default), just set your nightlight to manual timing from 3:59 to 3:58, then it’s effectively 24hrs.
There is an extension Toggle Night Light (casozbir) which gives you a simple ON/Off in the menu bar for those times when colour accuracy is important.
Im not sure about the night theme you mentioned, does nightlight activate dark mode? I didn’t know … perhaps there is an extension that will let you set the colour temp without nightlight.