Yeah, there's two values which pertains to Troop Type, the Indigo-Grey byte will always try to update itself whenever possible into the value up above. basically the first byte you're talking about is much more reliable to edit than the one inside the Grey box

For the Blue one indicating Infantry, I should point out there is another value up there for Unit Type, but maybe this value is used in game or something? Did you test it on a campaign? I was just testing through the CAW editor, still hadn't tried seeing in-game stuff.