ColorSource 20 AV

You have direct access to the channels and the playbacks, regardless of whether the faders are in channels or playbacks mode.

For channel control:

/cs/chan/at=x x: value [0-100],1 integer argument Puts the selected channel at level x
/cs/chan/wheel=x x: step amount [0-255],1 integer argument Steps the selected channel's level by x

For Playbacks:

/cs/playback/x/level = y 1 argument – level (float) Sets the level of playback x to value y (0.0 to 1.0)

See the OSC pages of the Help, on the console, via Amigo or here:
http://www.etcconnect.com/webdocs/Controls/ColorSourceAV_onlinehelp/en-us/Default.htm#CommandsOSC.html

You have direct access to the channels and the playbacks, regardless of whether the faders are in channels or playbacks mode.

For channel control:

/cs/chan/at=x x: value [0-100],1 integer argument Puts the selected channel at level x
/cs/chan/wheel=x x: step amount [0-255],1 integer argument Steps the selected channel's level by x

For Playbacks:

/cs/playback/x/level = y 1 argument – level (float) Sets the level of playback x to value y (0.0 to 1.0)

See the OSC pages of the Help, on the console, via Amigo or here:
http://www.etcconnect.com/webdocs/Controls/ColorSourceAV_onlinehelp/en-us/Default.htm#CommandsOSC.html

Thanks Richard for your answer!