The 8-way warning lamp system on a school bus typically sequences as the driver loads/unloads. What is the correct activation order?

1. Only red lamps are used; amber lamps are decorative
2. Red lamps first, then amber lamps after the door opens
3. White strobe first, then amber, then red simultaneously
4. Amber (yellow) warning lamps first, then red flashing lamps with stop arm and crossing gate