Diode Dynamics DD0227 HP3 Cool White BulbUpgrade. With this kit, you can easily convert the front end of your Mustang to an all LED, cool white modern appearance. These aren't your average turn signal bulbs they're Switchback! On the S550 Mustang, they will illuminate in a bright cool white color with your parking lights and headlights, then switch to intense amber when the turn signals are activated. The result is a modern dual color effect! Also included with the kit is a pair of 194 HP3