1. Check the backside of the doors over the kitchen countertop. Originally the coach's color scheme, paint colors, and their codes were printed onto a sheet of paper and affixed there.
2. Industrial Finishes (IF) in Bend and Eugene, OR supplies/supplied the paints for all the major coach lines in the area (PNW) and IF has various coach VIN numbers with the paint codes originally used on each coach. I assume IF has several offices spread around. Years ago I purchased a pint of each color for touching up our coach. They weren't cheap!
3. With these comments in mind, realize that after 20+ years since your coach was painted, the colors have likely faded. You may be better served to have a paint shop mix up paint to match the faded colors.
4. The external access door behind your fridge should have all the coach's exterior colors (probably four colors). Take that external door to a paint shop to get a good match.
5. The original paint used on our coach was Diamont, if memory serves.