Just say "look-a-like." That seems to work. It lets people know that it is close, but does not have the lineage and might not be the exact coral.
You can also just say the color(s) and the type of coral. Blue-Green Humilis, Blue Tip Prostata, Purple Nana, etc.
You can also just say the color(s) and the type of coral. Blue-Green Humilis, Blue Tip Prostata, Purple Nana, etc.