You are correct that they are tree frogs, indicated by expanded discs at the end of their digits. Hence, they belong to the genus
Litoria (which some taxonomists now call
Ranoidea). As was alluded to by Ryan-James, metamorphosing frogs can take a little time to attain adult colouration. This often make it difficult to correctly ID them at this stage. Secondly, given the circumstances, you may have more than one species present.
With
Litoria, apart from general colour and markings, important distinguishing features can include the colour of the armpit/shoulder, groin and thighs, whether the tympanum is readily visible or indistinct and what colour it is, the colour of the iris, whether the skin is granular or smooth on the on back and on the belly, and the degree of webbing of the feet. Your frogs would now be fully coloured and able to be more readily identified - it would be interesting to know what they turned out to be.
Based on what I can see here, I tend to agree with
Ryan-James and yourself,
addelinaperry, that they are most likely
L. caerulea. The larger metamorphs seem to lack the dark face stripe. In those two photos where it is present, it starts at the nostrils and does not seem to extend past the arm in at least one, which is consistent with juvenile
L. caerulea. The less clear individual appears to lack the gold line from the eye backwards, which is characteristic of Stream Frogs (
L. phyllochroa). Adults of this latter species are dark red on the armpits, groin and backs of the thighs, on contrast to
L. caerulea where these areas are green.
I really think they are litoria cerelea as they have begun emerging from the water and feeding on insects. They're starting to look and behave like my adult litoria cerelea.
