First we had the red zone, which was the cordoned off area in the central city. We still have that red zone, though it has shrunk over time, and is no longer guarded by the army.
Then we had another red zone, along with orange, green and white zones. This red zone, which is not the same as the first red zone, consists of residential areas where the land is too damaged to rebuild on without extensive repair work, and so the government is taking over all the land, and the residents have to move. The green zone is "OK to repair and rebuild", orange is "more information needed" and white is "not yet assessed" (mainly hill areas where there is a high risk of rockfall).
The orange areas were gradually being decided on and turning either red or green. And then on Friday we had a whole bunch more reassessments, so now we have red, a small area still orange, and a larger green area which is also either blue, yellow or grey.
Our near neighbours who were zoned orange are now zoned green (as we were, all along). But we are also blue which means supposedly that the land is at high risk of liquefaction in a future quake. (Despite the fact that we have had no liquefaction whatsoever in any of the 12 or so significant quakes, and around another 8000 aftershocks, so far.) It seems that this means that our repairs can go ahead as long as they don't involve foundations. If repairs to foundations are required, or significant rebuilding, then there will have to be a site-specific geotechnical report, and/or deep pile foundations, designed to new building standards that haven't actually been written yet.
For our own house, we should be OK, except that since we have new damage since our assessment was completed, we will probably have to be assessed again. EQC are claiming they will finish assessments by Christmas, but I think that means assessments from the February 22nd quake. So I have no idea when anything will happen about assessments from the June quake or October 5.5 aftershock.
The other likely consequence of being zoned blue, as far as I can see, is that our insurance premiums will go up significantly.
A small area on the west of the city is grey which means that no change is needed to foundation requirements. Most of the city is yellow which means slightly stricter standards which will supposedly add $5000 to the cost of building a house. As far as I can see, they are the standards that prevailed until twenty years or so ago anyway, when everything was relaxed and builders started putting a concrete slab on the ground instead of building proper foundations.
I'm not sure what it is with all the colours - the zones are TC1, TC2 and TC3 which would seem to be adequate without getting crayons out of the box, except that it does I suppose make it easier to display all the information on maps.