You must instantiate CANBusRedDetails, CANBusYellowDetails, CANBusGreenDetails and CANBusOrangeDetails before you use them.
CANBusRedDetails = new CANBusDetails;
CANBusYellowDetails = new CANBusDetails;
CANBusGreenDetails = new CANBusDetails;
CANBusOrangeDetails = new CANBusDetails;