Give RS Bikepaint a call and tell them make/model/year. They will most likely be able to match the paint, and they do aerosols for £10 a pop. They also do etch primer, rubbing compound, showroom polish etc so explain waht you want to do and they will get you set up. I've had paint from them for several bikes and I rate them. They also to touchup sticks, I just got a set (grey undercoat, blue and laquer) for the dark metallic blue monster and it's spot on. The red for my 749 is spot on too.
Number is on their website. They don;t do web sales because they like to make sure you are asking for the right colour and they guarantee the macth.
http://www.motorbikepaint.co.uk/