The more I think about it, THRAWN has synesthesia, specifically chromethesia, and gramapheme-color.
The basis of this idea is from the book AFTERMATH and thinking about how he would handle the Imperial navy the best over all other persons without the Sith.
He has a natural ability to have multiple senses where he has been taught how to use his ability strategically. It is the partial basis as to how he is a military genius that loves art.
What say you?