As far as I know there is Ducati "Rosso Red" that is used on pre-2001 bikes and "Anniversary Red" for later bikes (there may be more with newer bikes).
Rob is right though, depending on whether the bike has seen more sun, more miles, more polish, more T-cut or whatever the paintwork will have faded to a greater or lesser extent.
Halfords will be able to mix the paint, but only to a standard recipe, and you will find it is too orangey. What you really need to do if you really want an aerosol mixed up is go to an independant paint factor. Best if you can find one that is a distributor for PPG paint (that's Ducati's supplier). They will have swatches and devices that analyse the colour and will be able to do a custom tint for you. The paint will be just the colour coat, you will also need a compatible lacquer to get a decent finish because the idea is that you build a colour coat, flat it back so it's matt, then the lacquer makes it shiny again.
Mind you, if you're doing it from aerosol maybe you're not too fussy about an exact match ???
Bear in mind that Aerosol paint is simply pigment particles suspended in solvent and dries simply by the solvent evaporating leaving the pigment in place. It is nowhere near as tough as proper two-pack paint where the pigment carrier is mixed with a catalyst and the paint actually cures chemically once it is applied (a bit like epoxy resin). The paint factors won't sell you this stuff because it gives off cyanide based gases as it cures and unless you've got all the right breathing apparatus (no, not a B&Q dust mask) it'll kill ya. They'll only sell this stuff to professionals with properly equipped spray booths.
If you do spray it with aerosols, be prepared for the paint to flake straight off again at the merest hint of a stone chip.
Funnily enough though, and after saying all that, Halfords do carry aerosols of Bright Red Plastikote paint, which is a pretty good match once it's lacquered up.