If you go: Tools --> Options --> View and change the icon style to something else (Human, if you had it set to Tango, or Tango, if you had it set to Human) and then hover the mouse over the "New" button, its icon should change.
If you go:
Tools --> Options --> View
and change the icon style to something else (Human, if you had it set to Tango, or Tango, if you had it set to Human)
and then hover the mouse over the "New" button, its icon should change.