Alright, it's finally done! This piece was a lot of fun and an educational experience. Every letter, color, outline and shading was done completely freehand with either a brush or an airbrush. To give you an idea of the number of colors used, here's a list:
Starting with the Yellow vinyl...
Grey (mixed from black and white)
Purple (magenta mixed w/ process blue)
and a Sharpie
Many colors were used multiple times for fun. The last touch was cutting a few flame licks out of the Yellow vinyl, then drop shadowing them, then chasing the entire border with Magenta, then fading the flame tips in from Purple. Pretty freaking cool. I'm sure there's going to be some cool signs out there, but none as unique as this!