Bought it locally as an Indo for a low price. Now comparing it to Australia tusk photos, I believe I got lucky and was sold a Aussie.
It has the white stripes between the orange stripes but the white stripes turn blue as it approaches the dorsal fin. I believe that is the difference between the two?
Both types have blue teeth. The biggest difference is the Aust has the darker blue towards the back of the body and the orange is much more brighter. The thing is that most Indo come in on the smaller side, so they don't have the full colors, where the Aust tend to come in larger and have a lot of color on them. Depending on the size of the one that you have it's very possible you do have an Indo one but it has a lot of colors because it's larger than what you normally see with Indo.
A good way of getting an idea if it's an Indo or Aust is did the store just get in Aust Fish? Unless it's a big store I can't image them having both an Indo and Aust at the same time.