Colonies are small, nodular or encrusting.

It is pale or bluish, sometimes purple. It is similar in shape to the more common P. astreoides, but the latter is yellow-brown and forms larger colonies than P. branneri.

Blue colonies of very young Porites porites are also common, when these have yet to develop much branch structure. Some have referred to these as P. branneri on the basis of the colour, though its calice structure is different.