for the sake of discussion, flashing blue lights on a vehicle means police trying to pull you over or trying to tell you make way

flashing white light means an ambulance on an emergency and sometimes with flashing red

flashing yellow means slow moving equipment and a road hazard.

check with local regulations and the department of motor vehicles first.

on cars with seven wire system, the brake light works as signal lights, so, if you make them blink, it will be hazard lights since the seven wire system does not have dedicated amber turn signal/hazard lights