Use the document-open-recent icon instead of view-history on the "Recently Used" Kickoff tab. It's only a fine line between those two, and both would probably be suited for this, so I argue the change with the following two reasons:

a) Looks less sharp and black with the default Oxygen theme (making it look more in place with the other tabs, hopefully), but more importantly:
b) It's specified in the naming spec, and therefore should exist in a lot more themes than just Oxygen.