Chris which ones have you tried that have been unsuccessful? For instance, have you tried P. grandis of any type?

it is my understanding that those polyps which are pink or have pink in them tend to retain colors better in a low nutrient environment. That being the case, I would tend towards those colors.

Additionally, those polyps which exhibit a feeding response are most typically going to be any type of paly and the PE type zoanthids.

Therefore some thoughts;
Pink and Golds; if you're interested in trying these and there aren't any locally, I'd be happy to send you a frag for the cost of shipping. I'd love to see if they would pink up in your aquarium.

Hawaiian Ding Dang PE

White PE

Some others that I mights suggest that have done well in a buddies relatively low nutrient system are Vivid's Magenta, Tub's Blues, Eagle Eyes, Radioactive Dragon Eyes, Whammin Watermelon, and Cherry Bombs.