The White and Yellow has two functions, DRL and the turn signals. When you are driving straight, it lights up white. When you turn it flashing yellow light. The White Yellow Blue has three functions, DRL and the turn signals and night blue. When you are driving straight, it lights up white. When you turn it flashing yellow light.When you turn on headlight,it lights up blue. Fit for: Features: 100% brand new and high quality Adopt 100% brand new High quality High luminance LEDs Elaborate and easy installation design Bright LED consumes far less power than a standard bulb while maintaining optimal light output Waterproof lamp for all road weather conditions Bright with super beam daytime running light to driving safety Longer life LED lifetime up to 50,000 hours, minimal maintenance cost Enhance total appearances Extra cool white beam enhances to total appearance to your car Daytime running light improves safety while driving allows your vehicie to be seen at much further distances. Greatly improves reaction time of oncoming motorists in an incident Specification: Light Source:LED Material Type:Silicone LED