Varanus Gouldii Flavirufus are slightly smaller in size and they are more yellow and red in color, with different marking on their back and tails, as you can see in this photo of one that comes from Alice Springs NT.
Varanus Gouldii Gouldii can very in color from dark grey-black-brown with white or creamy spots and stripes all over their back and tail, they can also get mush bigger in size depending on where they come from natually in the wild.
The one you see in this photo come from chinaman Flat near Bendigo Victoria.
Thanks for that, was a bit unsure.
Before stating this thread I googled images but I found it hard to find photos of sub species as most of them were just titled Varanus Gouldii.