Bike body work
Essentially, if you are good with vehicle body work, you should be able to fix bicycle dings on a metal frame. I had a ding on the top tube of a PX10E that I filled in with a small amount of body filler before I did an entire repaint (covering whatever decals worth salvaging with masking tape first). I think top tubes are very susceptible to damage, especially on double butted tubing where the center points of the tubes are thinner walled because they don't need as much strength.
That color on your bike is a metallic. Even for a paint shop and a vehicle color code, that would be hard to repair without being noticeable. Since you are not a paint shop and there is no vehicle color code for a bike, you'll never get it perfect. You might want to look through rattle cans at your local autozone/advance autoparts/NAPA etc. for a similar color and practice first on a hunk of pipe. I usually create an aperture out of a piece of cardboard and hold it a few inches from whatever I'm painting and then spray through the aperture from a few more inches away to control where the paint goes.
Good luck.