Problem is that "Celeste" was a moving target: the Celeste color on your Bianchi may be quite different from that on another Bianchi from another year. If you really want a match, take your frame to an Auto painter with a spectometer (or whatever that device is called) that they use to scan paint and devise a mix-to-match formula. Then you can buy the paint (usually whatever brand/type they spray, maybe a synthetic lacquer or alkyd enamel) and some places can even make you up rattlecans of it, for an extra fee, if you don't have a compressor and spraygun.