From the Benellii paint codes you get Yellow Metallic GB022 which is Palinal 928.D.438
19 YELLOW MET BG022 B PALINAL 928.D.438 YELLOW AMAZONAS TL
Best of luck getting that!
I suggest that you take the bike, or part such as a mudguard, down to you local quality automotive paint supplier and get them to scan it in with a Spectrophotometer rand get a match.
I did get some paint that accurately matched using exactly that process..