The keyboard shortcut (<CTRL + <SHIFT> + A) is not working correctly in Creo 7.0.10.0 or Creo 9.0.7.0 . This sequence is documented to open the appearance gallery, but it is not working correctly. This shortcut when recorded in a mapkey sequence should open the appearance gallery but since it is not working correctly, I am not sure there is a workaround.
It looks like the shortcut is not working to spec.
I tried a few things in 9 and 11 and couldn't get it to work. The best I could do was get the appearances button to be selected so you could pick something but I couldn't get the dialog box to open.