I was just at a big shipper in BKK today and he has been getting some fish from us for a while. He said that the infection we are seeing is very easy to treat but with only high end meds. He treats the fish with 500mg Zmax pills or AZITHROMYCIN. At 500mg pet 10 gal of water. Every 24 hours for 5 days. Then he bring the temp to 89 for 2 days with clean water and looks for any fish that need a second run. It seems this is the same for a lot of Thai exporters. So this is not a color thing I am told. Hope this helps.