You can get a fan deck of the FS color specification system. The fan deck is (or was, when I bought mine—years ago)l relatively inexpensive. If you know the FS color number used on the actual plane, you can use the fan deck to match it. Bring the fan deck with you to the contest. Anyone says your color is inaccurate, show them that it's not.

As BarleyBop said, you will never find that color on an actual plane, except maybe on one just out of the paint shop—if you are very lucky and the gods want to tease you. In fact, as a former paint technologist, I'd say his estimate of the reasons against is quite conservative.