They are in the back of the owners manual. If you don't have said manual you can download a PDF copy from www.ducati.com although having said that i think they only go back as far as 2000.
The PPG paint code for red up to '98 is 473.101 From '99 on it is 487.111 Unfortunately as a '98 model, your's may be either. If its yellow it is 473.201