Advance Sprite Palettes

Do I have to do something special to make the game use Locke's color palette on Edgar and Sabin? Can I even do that?

This is a common question. There is the battle palette and field palette IDs. The battle palette ID can be changed with FF3usME/FF6Tools (I think) but the field one is assigned by event at character recruit. Check the palette document by runelancer here: https://www.ff6hacking.com/wiki/doku.php...s:doc:game

It will tell you where in the event banks palette for each character is assigned. This can be edited with FF6Tools event editor I think or worst case scenario with a hex editor. You'll need to test with a save file prior to the character recruit because the field palette ID is saved in SRAM.