Oh maaaaaaaaaaaaaaan haha, Im the Zoa addict to talk to about that
Zoanthids also referred to "Zoas" for short slang. Are an easier type of coral to grow, unlike sps switch needs a consistent stable environment, they are able to deal with various amount in swings in water as well as have noticeable growth.
Any color you can possibly think of Zoanthids/Palythoa, (Simliar species as zoanthids but have a tendency to be bigger in polyp size and 9/10 times have a much more stronger toxins) or also known as "Paly" for slang, have those colors plus more. They are known as a soft coral or "Polyp coral" and grow in a mat which means that just over many various obstacles that lay around them.
Some will lay dominate for a while and will not grow for a month or longer while other are more invasive and will spread throughout the tank like wild fire. The corals that are invasive have a much potent toxin called polyp toxin. YOU DO NOT WANT THIS ON YOUR SKIN NOR EVEN INSIDE OF YOU.
When you collect them and arrange them into groups, you could say it resembles a bouquet of flowers between the various color that compliment each other and that why meany people are so attracted to them such as myself.
Edit: Here are some link to check out:
http://www.atlantareefclub.org/forums/showthread.php?t=88289&highlight=collection
http://www.reef2reef.com/forums/zoa-discussion-club-zoa/98197-zoa-dominated-125g.html