To my eye at first N. irenica seemed the better match of the two, but this moth has grey colouring along the outer forewing margin which is not apparent in other online examples https://www.inaturalist.org/observations/259295288 although the Bold (Hobern) examples are overall much darker https://bold-au.hobern.net/specimens.php?taxid=328089 Although N, paromoea example though may be the closest match and includes the brownish and grey tones https://www.inaturalist.org/observations/112906728
Are you talking about the blue grey hue of the fringe and terminal area ? I think that is a function of the lighting and focus. The sheet which I presume was white is also grey/blue. I too can see points for both species. Maybe a way to split it is that in Moths of Vic. - N. irenica is found in alpine areas (and the Grampians) N. paromoea is found quite boadly - from the Mallee to the sea. Is Bolivia, NSW 'alpine' ? or not
Wendy, I do not think you would class it as alpine. Though I have not experienced it, snow may be a rarity. I have been there in frost at -5° and believe it may reach -10°