Our Junior Members wear Black Helmets like everyone else, but with an orange front piece that has a big white J on it. Above the J is the name of the department and below it is the rank Junior. This is similar to our adult probationary members who wear the same except the shield has a P and says Probationary under it.
By doing this, your helmet stays with you throughout your membership, this was a big issue for allot of members from a sentimental / historical perspective. So now you start with orange (J), move up to orange (P) at 18, then get a black front piece when you come off probation and in theory a white front piece if you become an officer.
In my department, Explorers have orange Firedome helmets with Explorer on the sides and the department crest on the front, but if we buy our own helmets, we are allowed to use them. Probies and up have 1010s. Probie and firefighter helmets are yellow. Probies have black shields and ff's have orange shields. Captains are red with white shields and chiefs have white with white.
Our explorers do not have structure type helmets. We do have bullard cap style veg helmets but thats about it. We all have full structure and wildland gear/PPE except for structure helmet. I personally have a red Cairns helmet I use for training as well as a black Cairns helmet for the same purpose.