http command to turn off multiple channels

So I've run out of actions to turn off all the lights in my living room so I wonder if it's possible to turn off multiple channels of an RGBW2 in white mode in one command?

Looking at the docs and guides I tried this:

http://192.168.111.222/white/0?turn=o…=off&2?turn=off

It's accepted but only turns off the first channel, any ideas? I don't really want to get my openhab automation system involved and I don't use the Shelly Cloud either, looking to do this as directly as possible.

I'm using button two on a Dimmer 2 to turn off the dimmer (so I waste one action because the button has to be detatched, why exactly?) then a tasmota ceiling fan, three channels of the RGBW2 and a standard lamp controlled by dimmer 2's. It all fits if I can turn off the RGBW2 in one command.

Nope, same situation, no error but only channel 0 turns off, thanks but that's not the answer.

I have too much load to wire all the strips on one channel but I wonder if I can fudge it in colour mode, maybe if I wire the three strips to RGB I can still fade them etc.

Would be better to just switch them on and off, fade them up and down as a group, without any fudging.

Does anyone know what happens with the button input? Does that switch them all off together? If so Can I send a button off command, maybe.

There has to be a way to do this surely.

I also tried:

http://192.168.214.219/white/0?turn=o…hite/2?turn=off

same

So I tried Color mode, better but now some weirdness which is most likely a failure to understand on my part.

In Color mode I can switch on/off and it does all channels together, excellent. I even get night mode which 4 channel mode doesn't have.

http://192.168.214.219/color/0?turn=off

I can manually set the colour picker to white, for some reason there isn't a white button on the web interface!

http://192.168.214.219/color/0?red=25…ue=255&gain=100

Now trying to change the brightness is a bit odd, seems I should use gain but it seems to work sometimes and not others, probably a shelly integration with Openhab problem