Hi there,
Nick. Welcome to RetouchPRO
No problem....
1) Your
first step when you
first decided to blur the Green channel was to duplicate the original layer -
wasn't it?
You now have two options open for you....
2a) Do what ever you want to do with the Green channel on the new layer and apply a layer mask as normal. For the Red and Blue channels (which haven't been changed) it won't make any difference whether they are masked or not, while for the Green channel the effect gets masked properly;
..or better..
2b) In your new layer open up the blending options (right click on the layer) and uncheck the R and B boxes. Now you can do whatever you want without worrying about channels at all -
only the Green channel counts. Good thing with this is that you're not restricted to channels and so this way
all of the tools will work.
Hope this helps.
Rô