During WW1, aces of both sides flew aircraft with different colors or national markings.
For example, many American pilots flew with either the Brits or French, then in 1918, switched over to American Units.
There is circumstancial evidence to suggest that SE5a's converted to the American Star just prior to war's end. So Elliot White Springs will need TWO
A dark green one with Brit roundels & his personal markings, and a tan color one with the American Star when he switched to 148th Aero Squadron.
Of course, the most obvious example of paint scheme changing has to go to Ernst Udet, who had his own personal luftwaffe.
For example, Ernst Udet's Alb D5a had at least 2 color schemes, one black, the other white, and 3 Dr1 schemes, etc.
Aces having multiple schemes can be done via a date feature. This shouldn't be too difficult to do, I would think.