I managed to scratch my Blue RST, when I got the frame I also got a touch up pot. While the touch up colour is blue it does not match the frame colour (not even close). Go to a motor factors and have a look though the car touch ups, the blue of my bike is very close to the metallic blue they used to spray Vauxhall Corsa's in. Get one with a brush rather than a spray it is much easier to apply on small area's.
Peter