Look at one of your themes that is 3 states. If the states are placed horizontally, divide the total image width by 3. That will tell you how big each state is. Double the canvas width to accommodate 6 states and copy/paste/modify/reposition the states. If the states are placed vertically, same process only image/canvas height.
Example: The 3 state image is 150 wide. 150/3=50 per state. 50x6=300 6 state image width.
I believe the 6 state image frames are as follows:
1 - Selected File "Clicked Off" (Active Window). Shows when you've selected a file then click in an open area in the Explorer window.
2 - Mouseover on unselected files (Active and Inactive Window)
3 - Selected group (Active Window)_
4 - Not used
5 - Selected (Inactive Window, both Single File and Group)
6 - Selected single file (Active Window) and SelectedMouseover (Active and Inactive Window)