Gorgeous! How hard are they to grow, do you think?
I've had a bit more of a trawl through the interweb and they are actually ornamental cabbages not cabbage roses at all! I found this http://www.ehow.com/how_8122312_grow-ornamental-cabbage.html about growing them and I think Australian/ New Zealand conditions would be perfect temperature-wise but they do sound a little hit-or-miss. Apparently they're edible but not as nice as regular cabbage. There must be some clever way to use them as a garnish but I think thye would be just as nice brightening up the veggie patch just like rainbow silverbeet. I've also noticed lots of orange and purple cauliflowers in the shops this year.
They look gorgeous..amazing colours, especially with the light shining on them. I didn't know that they are edible. I have planted ones that I've bought from flower markets or garden centres in the past in pots for autumn colour but always thought that they were just ornamental. We get those lovely little purple and green cauliflower's too....I used to get them in my veg box and would keep them for ages before cooking because they looked so lovely in the kitchen.