This is beautiful. Does anyone know how many of those colors are believed to be historically accurate representations vs artistic license? The paint has long s

This is beautiful. Does anyone know how many of those colors are believed to be historically accurate representations vs artistic license? The paint has long since faded, but perhaps the colors have been identified through some kind of anlysis? There was a recent article here on HN which made me realize the importance of communicating what colors are scientifically or historically accurate vs artistic license.