Charred is a very deep charcoal (it's not quite black) with a slight sheen and heavy silvery sparkle overlay. It's listed on the back as a Frost finish but it's definitely more like the Lustre finish. It's harder than most of the other Frosts I have from MAC and needs some coaxing to be shown at its best.
A primer is most definitely needed with Charred. The base colour is so sheer on its own that it just blends away to nothing. It needs the base to stick. Also the silver sparkle just floats away and falls over your face if it's not stuck to a primer. With a decent primer (something nicely sticky like NYX Jumbo Eye Pencils or Fyrinnae Pixie Epoxy) you get a quite interesting deep sparkly charcoal to use to create a smokey eye. I still find that you can't blend the shadow too much even with a primer or the silver sparkle works itself loose and you get it dropping off your lid.
MAC Shadows are available from MAC (website/stores/counters):
-Pro pans are £10.00
-Pots are £12.00