Rustoleum's Metallic # 7271830 - Silver Metallic, or Professional Metallic # 244493 - Silver Metallic spray can is said to be a perfect match in the Thumpertalk forum for Kawasaki's # 458 Metallic Phantom Silver color as used on Kawasaki KX frames... It rated better than other compared brands in terms of durability and metallic flake size:
Dupli-Color Ultra Silver T191 'Truck, Van & SUV' premium acrylic lacquer. It's pretty close to Rust-Oleum's Silver Metallic 7271830, and it covers a bit better :
Sky Pirate: "My personal favorite, in spite of being more challenging to work with... Most durable against chemicals. Can recoat any time."
I ended up getting a can of locally available Dupli-Color 'Radiant Silver' T347 which has more texture than two other 'Silver' variants. It (and Rust-Oleum's) may not be identical to original Phantom Silver, but I'll be painting the entire swingarm, footpeg mounts and handlebar mount... It's used to match Audi's silver as see here: