Are you referring to pink Anthelia? If so, it will open up as soon as it adjusts, usually in a few days. Many people consider this species a "weed" coral. I personally think it looks amazing under the right LED lights - it gets a purplish sheen to it. It doesn't require a lot of light. When it gets "barely" enough light, it will get big and mostly translucent, not very attractive. Keeping it under brighter light will keep the polyps smaller and beautiful (colorful and shiny!).
Once settled, it should grow quickly for you, but don't place it too close to SPS, as it may try to take over the SPS. During nighttime, many SPS will get defensive and sting the Anthelia, killing it back. That said, it causes undue stress on both corals.
Hope that helps?
Jeff