I wore a lot of greens this past December, but I never wore olive!  MAC Seriously Hip (Style Black, Fall 2009) is a blackened olive green shimmer with tiny gold flaky glitter:

Picture taken in sunlight.  Application was really good; I got full coverage in two coats, though I almost got away with just one.  I think this polish is aptly named; it is SO cool!  I love blackened shades like this, and the flaky glitter looks so interesting.  It’s another one of those colors that looks simply amazing when it catches the light.  This is definitely one of my favorite MAC polishes.  I paired this with Sephora by OPI Charge It! on my toes.