Okay, my Brain just BLEW UP!  How.......How did you get the grey and black lines (?) or swishes (?), or whatever they are called, INTO what I am assuming is fondant?  I absolutely LOVE this cake!  And I don't know why.

Bravo!  Well Done!  Gorgeous!

P.S.  Seriously, how did you DO that?

lvdenver - you are too kind!!  Glad to provide the details, but it's honestly super simple.  Really!!  If you look closely, you can see that this is buttercream.  Fondant would definitely be better, but this was just very cold therefore very stiff buttercream.  So that's step #1:  Refigerate (not freeze) your BC-iced cake. Or use fondant which would definitely create a better result.   My bride wanted BC, so I didn't need to choose between the two.  Step #2 is taking black, silver, (red would be an awesome addition as would purple), etc, and dilute the colors (AmeriColor gels in this case) with vodka or, what I always use is peppermint schnapps.  It smells wonderful and dries even quicker, so I choose peppermint schnapps pretty much always.  Then Step #3 is picking paint brushes.  Use a variety, because each brush's width and tip creates a different type of line.  So dip any brush in any color, and paint a random pattern. Don't overthink it.  Just dip and brush.  Repeat.   Then, Step #4 -  load up any brush or brushes with a hefty dose of color and spatter it randomly anywhere and everywhere.  Learn from my inexperience and put something - anything - behind the cake when you splatter, because I was cleaning up spots of "paint" for weeks afterwards!!  The great news about this style is that anything you do is what makes it beautiful and unique.  The bad news about this style is that you don't get do-overs.  Once you have added a brush stroke or splatter, you don't get an eraser!!  Channel your inner kindergarten self, and have fun!!