I put orange juice to the test using my blueberry juice indicator. Orange juice contains citric acid, like most fruits. Although the acid is a weak acid, it can still irritate the eyes if they come in contact with it.
Here were the acidity results.

*In fake newscast voice* You can always trust Oasis-brand orange juice to be the best.

A sample of orange juice

What the orange juice looked like after adding a few drops of blueberry juice

What the orange juice looked like after mixing it with the blueberry juice

The blueberry juice had turned into brighter and lighter shade of red, which confirmed that the orange juice was acidic.