It might be worth your while checking out RS Bike paint.
http://www.rsbikepaint.com/en-gb/colours.php#makeid=103&modelid=3185&prodyear=2003.
I’m sure I’ve seen that colour on modern Vespas so it’s probably a Piaggio colour. Cant be unique to Breva footrest hangers. Didn’t some of the Brevas come in that colour with Red Wheels.
Mine is a 2008 model with a Black Tank and seat tail and springs on the Hagon Shocks. When I get round to fixing the scabby silver hangers, I will do them and the fork sliders in Black. Possibly the Wheels as well, a sort of home made "Breva Dark.
Nigel at NBS found the colour as he refinished my rocker covers for me !
might be worth ringing him
or take it to a paint specialist for colour matching