Added xrandr --output eDP-1 --gamma 0.9:0.85:0.9 to the start up commands but its not executing on startup, even when xset m 0/1 0 executes.
Some commands always needed some delay for me, so try adding sleep 3 && before the command.
Other option to try is to make a new file in home (eg. Startup.sh). Open it with scratch and instert:
#!/bin/bash Your command
Make the file executable (e.g. with right click-> properties) and put the location of the file in startup applications /home/your name/startup.sh
You can even try combining the two, adding sleep 3 && before your command in the file.