Old, sturdy, true-blue, double-dyed Presbyterians, they held stoutly by their own views of duty as well as doctrine.
That is not to say he is n't a true-blue Aussie.
For example, using a true blue eye shadow on blue-green eyes can actually make the color look dull and washed out, as opposed to rich and vibrant.
The expression true blue comes from the blue sapphire's symbolism.