These frogs were in a bathtub in the paddock and were making the call of a Screaming Tree frog although they stopped when we got close. I have never seen them this colour before, the ones I have seen previously have been brown with darker brown markings on them. Someone told me that they are this yellow/green colour during the breeding season?
As you've heard, the yellow colouration is sometimes observed in breeding males of this species, although this specimen lacks most, if not all patterning, which I haven't seen before. Other than that there's nothing that I can see that suggests anything other than L. quiritatus. Since you heard the call and it's so distinctive, I think it's reasonable to at least pencil this in as this species.