Columnaris usually fluffy in appearance, it's not just a change in scale color. I've come across the change in scale color multiple times and it hasn't seen a cure thus far but it doesn't effect them, it usually effects the scales right around the top of the dorsal and then will turn the first few rays/mebrane of the dorsal white along with it, this would be the third one I've seen happen over the last two months and I've not no idea what it is but salt did nothing for it and nor did KanaPlex or General Cure, but it never effected the fish and the fin didn't fall off or anything.
So that said, I would leave all the antibiotics and salt out of the water for now, keep an eye on the patch to see what happens but if it's purely discoloration and nothing raised on it, slimy or bumpy or fluffy then I wouldn't worry. What you need to focus on is just the water quality and keeping her in good clean water until she feels better and she can start fighting off whatever it is.
By the way, that picture is totally awesome, you definitely get fish keeper of the year!! haha
I hope everything works out though!
And yes if you have IAL, use that instead of the green tea, it does the same thing but there's no point in using it if you already have IAL. And the green tea also must be pure 100% decaffeinated green tea.