The Colonel is the guy who initially dreamed up the scheme to relieve Emily of her tax obligations when her father died. And sure, that was a nice thing to do.
But, the Colonel is also the guy who "fathered the edict that no N**** woman should appear on the streets without an apron" (1.3).
That's, um, not so nice. In fact, that's despicable and deeply racist.
Unfortunately, virulent racism and bigotry was all too normal when it came to turn-of-the-century Southern political figures, and the narration of "A Rose For Emily" doesn't interrogate the Colonel's morals.