what is the size of your tank 20 herms thats allot I have about 10 in a 110g maybe they are checking out the new corals and irritating them. Colt corals are funny some people can grow them and some just can't get them to live.
I know a guy that can't get Athelia to grow it keeps dieing.

I would also raise the salinity to 1.025 are you using a refractometer?

by the way nice carpet Nem there. other than those 2 corals the rest of your tank looks nice. I'd give it a couple more days, The colt coral can take awhile to open up.
Bill