The tall palms that I have seen in the islands have green trunks and are red at the top. I believe this is how they grow.
t-

hi
May not be your problem but they vary considerably in the amount of red some are even all green there are also yellow and orange cultivars.
Pretty rare palm in florida but you might check out the Fairchild gardens site for suggestions gary

Sealing Wax palms, as they mature, become green on the oldest part of the trunk. They can literally become half green trunked and half red trunked. You are doing nothing wrong. It's just the way the palm grows.

Steve