I have the silver one... CW to lower boost and CCW for raise boost... I remember by thinking "tighten turns off the boost" just like a faucet turns off the water...
I put a black mark on mine [like the minute hand on a clock], so that I know how many times I'm turning it.
In order to get 0.95 BAR boost, I tighten all the way and "loosen" a full 2.5-turns...
It has a locking screw [alan head] that I use to lock it in place... I have a 3-yr old that sits back there and I'm afraid he may go to turning it - so, that eliminates that possibility...