Yes, that should be the case 🙂
The Coles Mobile website does say: The Coles Prepaid SIM is a multi-fit SIM, which means it will work in any unlocked mobile device which uses a standard, micro, or nano SIM. Device compatibility and location will determine which mobile network coverage you will receive. Find out more about the Optus network here.
however this must be referring to using a non Optus purchased device.