Jaykellogg has a point. If you fix the source of the spot and seal the stain, it may even match. If it won't match, paint the small area the original ceiling color. You fixed it to all codes I know of, and their lifestyle will blend it in, within a year or two. My youngest son went to an art collage. They trained him to properly match any color, it can be done; but that color won't age the same as the rest of the ceiling anyway and will show in a year or so.
As far as the textured ceiling goes, Drywall Joint Compound, or Combination Joint Compound thinned with small!! amounts of water is mostly what the pros use. DO NOT USE "Top Coat" it is way too yellow and way too soft. I put on a layer about 1/8 to 1/4 inch thick then texture to blend in. Use an old brush (that was soaked for hours then shaken or spun dry, or notched tooth mastic trowel, or a funky roller, I've matched the rosettes with my wetted thumb. You can practice on scraps of drywall. When I did this for money, every spring I was in big demand, because I was better that most "Painters" or textured ceiling guys (they do new work, not repairs). Ivan