What would you do if it was your car? Some body coloured polish and a bit of T-Cut maybe! How about touch up paint?
Yes, with a bit of luck you can fix it yourself. Maybe so that you can only tell close up. See here:
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I could have done a better job, taken more time, filled it first done losts of rubbing down etc, but I was happy with the result. No 1 tip: Use the fine nib and not the brush, take your time.
The key thing is to find the best paint match. If the bike manufacturer does not supply paint, then you need to get yourself down to Halfords (a motor parts and other stuff retailer). They have a very wide range of car paints both in touch up and spray. I took a photo for comparison, but I have also taken the whole bike in to the shop on occasions. Beware of the odd lighting in shops, it is nothing like normal outdoor light, ask to take the paint sample and the bike outside to check. (Or pay for it and get a refund if they are being an arse).
I thought with a German bike (the blue bike above was a Focus Jam2) that German car brands would be the answer, but it turned out to be a French (Peugot) colour that was a perfect match.
By the time you have applied some helicopter tape (stable doors etc) you will not be able to tell!
Good luck with the search!