I am controlling my PC with SSH and scripting. How can i change the brightness, color and sharpness from command line?

Try 1: failed

$ sudo redshift -t 5000:5000 -g .5

Cannot list GNOME panel applets.

Initialization of gnome-clock failed.

Trying next provider...

Latitude and longitude must be set.

Try 2: failed

$ cat brightness 

20

$ cat max_brightness 

20

$ echo 1 | sudo tee /sys/class/backlight/acpi_video0/brightness 

1

$ echo 20 | sudo tee /sys/class/backlight/acpi_video0/brightness 

Any alternative way to do?

Follow up: http://jonls.dk/redshift/

[command]     [1000K to 10000K]       [effects 0.1 to 10.0]

|       |     /      /                /

^       ^     ^      ^                ^

redshift  -t  1000:1000   -l 0:0  -g .1; Dark

redshift  -t  1000:1000   -l 0.0  -g  5; Bright