Silhouettes

It colors that Sabin NPC (or is it vargas...?) black by entrance event. Palete 6 is a placeholder palette that is coded to color the sprite depending on what the entrance event code tells it to color it as. If there is no entrance event code that modifies the background color range, it will not affect the palette 6 object/npc. So you would want to put your npc as palette 6, and then edit an entrance event for that map that modifies the background color range to your choice of palette, which would affect anything that is palette 6 on that map.

here's a thread that goes into a bit more detail about palette 6 and entrance events:
https://www.ff6hacking.com/forums/showth...nce+events