worth a try to send in a request as they custom make each application. Don't have my smart yet otherwise I would send one in myself (plan to own a black/silver passion). Have had excellent results using their products on my '98 New Beetle (bright red, no longer owned) as well as my '99 Miata (dark twilight blue) for most rock chips (worked well on the Miata hardtop which I would think would be pretty close to the composite used on the smart). Works different that a regular touch-up brush as it leaves no brush stroke marks (the Miata club guys like it a lot) it just fills in the void left by the chip.
http://www.autovisuals.com/paintcode-help.asp
I'm sure they would add the smart as soon as they get more requests as they also list the '98 MBZ colors