First off, while these Sierra headlights are $1200 EACH from the dealership...the internals are pretty much junk. The factory 25w HID projectors are better than what most people are used to....but for actual on-road use, they don't put out a whole lot of light.
So I junked those and swapped in some Morimoto D2S Projectors with 35w D2S Bulbs and Hylux 35w ballasts....this will provide a MUCH cleaner, wider and further output over the stock unit.
Then I upgraded the factory DRL boards, as usual. Normally these are just White....but to make them brighter and cooler, I upgraded the boards to the Diode Dynamic switchback boards...so now they are WHITE for running/DRLs and then AMBER for turn signals.
Also upgraded was the factory turn signal bulb....which is not a switchback bulb as well....so everything internally is either WHITE or AMBER to match each other.
The internal shroud was painted Gloss Black and all three lenses were replaced with White Frosted replacements from Klearz.