Good call, Bandy.
In another life, I used to be a State Govt. forensic scientist.
Paint matching is absolutely routine.
Examples include paint fragments recovered from a suspect's clothes with that from crime scene window frames or sills, paint particles identified in car collisions (with buildings, other vehicles, victims of hit-&-runs) etc.
https://en.wikipedia.org/wiki/Micro-spectrophotometry
Should be entirely possible.
Dean
(Of course, the flaperon and wing may have been painted at different times or locations, but the paint batches involved should be traceable - they would paint a whole bunch of flaperons at the same time with the same spectroscopically-identifiable batch)