We have a '19 serenity, which has the light color interior.
As mentioned, take the time to find the International that appeals to YOU.
Since your trying to flip it in a very short period of time (in Airstream years), don't change anything or else you will have a very narrow buyers market when you want to flip it.
Nobody cares about your vision and how beautiful you made it to suit you. Perspective buyers will want it as close to the original configuration from the factory and not have to deal with added layers of non factory modifications......including paint.
Don't mean to sound harsh, but if you said you were keeping it for a few decades....then it would make sense, but since your have a short own time....it doesn't make sense.
Good luck in your quest, be interesting to see where you land.