Gaddafi has tried, but he can't ruin the colour green.Gum Leaf Katydid - Torbia viridissima
Even the elytra are green-veined.
See the Chew family's charming, informative, and extensively illustrated page about these katydids, complete with pictures and an account of egg-laying, here. It is part of their always fascinating Brisbane Insects site.
I'd never seen a katydid this large, but found the one above on a forest path–and like sometime revolutions, another one just moments and metres away.