You should be able to get palm specific fertilisers. But it does sound like there may be an iron chlorosis problem. Iron can be bound up in some soils and not available to plants. Chelated iron is usually good in those situations. It would also be helpful if you said where you were and what climate you're in. And photos would help as well.

Thank you, will try to get some photos tonight, was bucketing down rain last night. We live in New Zealand, bay of Plenty area, right on the coast.

Its winter. They usually don't have the good green color they have in warmer months. They cant uptake nutrients in our cool winters to look top notch. They also have only seen rains this past month..before that they might have gone very dry as the house was for sale.

But - they still look very healthy. Yellowing on rain forest palms in California is common in winter.

Oop. Your down south. That would be summer for you. Still,they look pretty good. Maybe a need for some fertilizing- any good brand for palms would green them up.

Also,I see only older lower fronds that are worn..maybe just prune them off,and dose with fertilizer and you are back to top notch palms.