Send a pic please. I repair this type of damage to Ducati’s all the time. It’s always caused by crash damage. No paint code, it has to be matched but is not difficult. If done correctly painting will be minimal. Make sure it’s not just the paint that’s cracked, which can give the appearance of the frame cracking, seen that lots of times. 999 has totally different peg mounting setup on the frame.
Firstly put a long 8mm bolt in the upper and lower holes. Make sure thy are parallel when looked at from different angles. Straighten if needed. To be done properly the swinger should be removed but if you can’t, the crack underneath can still be welded. A competent TIG welder should be able to do it easily with minimal heat damage to the paint but you will still need the area cleaned and painted. Again, a competent person should be able to blend a 30mm area without it being visible. Hope this helped.