Your Acrylistix already has two subs, one for light and one for dark. So I assume you made the light one than went into SubStyle Management and created a new sub for the dark changing the graphics. Say one of your other subs within the four on you other wb is for xp. You just can't make it as a separate WB and add it to another WB. (at least that is what I was told by a couple masters a few years ago when I asked the same question)
Say you want to add a new sub for xp. You open your wb and make a new sub called Acrylistix xp. Now you have to make all the changes in that sub only. One step further. You want to make a xp sub for each light and dark. So you open your original. Now you make a sub Acrylistix Light xp and make all your changes. If you want the same for your dark you have to make another sub for that and make the changes.
If you already have a completed wb with the four additional sub it would be faster to just do something like Uvah said and call it Acrylistix 2 or something. You can describ what is within that Wb in the description.
Bottom line is you have the original wb add a sub and make the changes as to what the sub to be for every sub you add.
