Which language?

[Bob]

The hero of my series is an Australian, like I am, so the book is written in that language. This seems wrong when a scene is presented from the point of view of an American character, so I've written those sections in US English.
I'd appreciate opinions on whether I should stay in the same version of English throughout, or to switch like this so I am staying in the reality of the witness to the scene.
:)
Bob

[Emma]

Stick with the same type of English, if you suddenly change the way you spell certain words it'll look odd.
However, make sure the characters 'sound' authentic to their origin. I'd have a native American speaker check your dialogue for consistency so your American characters sound American, and not Australian.

[Bob]

Thank you for the response, Emma and LJ. I am multilingual in English, doing editing for US, Canadian, British and even Indian clients. All these Englishes are different, though US is more different than most!
It does look odd on the page, though, when a boy from Iowa says "...colour..."
:)
Bob

[Emma]

But it would sound the same....