Blue symphodium. One of my favorite corals when I discovered the stuff. Beautiful polyps and it is much more slow growing than any polyp I've seen. Grows in short stalks and they form little 'puffs'.
They are hardy, but a drastic swing can be deadly. I almost wiped mine out when I plunged my nitrates and was raising all a tad. Half of it died in what looked like a fungus, but by blowing the dying off it was able to recover.
Wow! Really nice! Was the variety you had all blue? Searching I only found 1 picture of an all blue variety from an old eBay picture. Every other result only pulls up blue-green. It looks like a really nice coral especially to add color into blank areas.
That's the stuff. It is the only color I'm aware of. It is easy to drag too. I had it grow on a snail she'll and when the shell lost balance to fall. It over the course of a month dripped down like molasses until it snapped off and grew in the sand on the shell.
I think I'm going to get a frag of the coral you mentioned. The BCP and blue snowflake both worry me because of how quickly they populate. I love the idea of the blue covering open rock but I don't like the idea of it growing over other corals.