Does Rally the Righteous affect heroic?
Rally the Righteous only targets one creature, and so it'll only trigger heroic on that specific creature. It says "untap target creature" &mdash; that's the one that gets targeted. It then further says "and each other creature that shares a color with it" &mdash; but it doesn't say "target" in that phrase anywhere, so you're not targeting any of those other creatures. (If it was targeting, it'd say something ike "each other target creature".)

If you target a multicolored creature, like the spell says, it'll affect any creature that shares any color with the one you untap. If you untap a red/white creature, you'll untap red creatures, white creatures, red/white creatures, red/blue, white/black, etc etc &mdash; because all of those have a color of at least red or white.