Diode Dynamics DD0462P BulbsUpgrade. Add dual color functionality and a modern appearance to your front turn signals with the 4257 HP24 turn signal bulb. Populated with sixteen amber chips and eight white chips, this bulb lights up white when your headlights are turned on, and flashes amber when the turn signals are activated. Housed in an aluminum casing for maximum heatsinking properties, the HP24 will last for years to come. Best of all, installation only takes minutes simply