Nikau palm

Dypsis palm

all look like sunburn... any direct sunlight? or freezing? Try to avoid both in all these palms, though the Dypsis lutescens should quickly adapt to sunlight if kept moist enough (may take 6 months... which is 'quick' for a palm).

Whereabouts are you, North Island, South Island? Can't imagine why Nikau should have problems. If those plants were growing in a nursery in complete shade before you got them then they need to be slowly acclimatised to sunlight. They will all grow in full sun, eventually. The ideal way is while they're still in pots you move them inceasingly into the sun over a few months or so. Morning sun is better at the start. New sun resistant fronds will grow but plant development will have been slowed down.

More water. They are probably going dry along with the now full sun.