For best results the LED color should be the same as the lens color or if bulb is behind a clear lens, use the appropriate color for turn and brake light functions. As an example: a red lens will filter out all but the red portion of the light so if the light is all red, none or very little light will be blocked by the lens. The light from a White LED contains very little light in the red portion of the visible spectrum so most of the light would be filtered out by a red lens. In additional, usually the lens are designed in some optical theory such as reflection, the original color( red lens and red LED) creates the best result. (Bulb Color = Lens Color unless Lens is Clear. Bulb Colors = Lens Colors unless Lens is water clear.)