After my last 3 Audi's I found the stock USA 4150K color temperature HID bulbs in my 2012 Touareg rather yellow. So I ordered a couple very white (but not blue) 6000k D3S bulbs for $150 from these guys:
Philips D3S Replacement HID Bulbs
The driver's side install was a little fiddly but not too bad, while the passenger side was quite the pain. I couldn't find instructions on how to change the HID bulbs for the 2011+ Touareg so I just winged it (the manual tells you how to change halogen bulbs but that HID are for the dealer). I did not remove the headlight assemblies like on the older model Touaregs as it seems you'd have to remove the grill and possibly bumper.
Directly behind each headlight is a rectangular hatch, you have to remove two screws on the top two corners then press a latch in the top center. This allows the hatch to hinge rearward on bottom tabs, then be rotated out of the way enough to access the bulb. The bulb rotates 45 deg counter clockwise to come out, then you gently remove the wire retaining clip and pull the wire, then remove the mounting ring with the one obvious clip. The couple gotchas are:
1) On the outboard screws on both headlights there is not enough room to use a screw driver. I used a couple-inch long hex bit with the T15 Torx on one end and a small ratcheting wrench on the other.
2) On the passenger side I had to remove the air filter box. The two obvious top clips allow the cover and air filter to be removed. Then there is one upper front bolt that allows the filter box to be pulled upward once the air intake hose clamp and a couple other wires are disconnected. The trickiest part was getting the box reconnected to its intake, I end up reaching through the box into the intake and making a fist to pull the intake onto the box. Took a few tries. Once the intake was connected to the box then it sat back into its bottom pin holes, got bolted on the top front, had the wires reconnected and was good to go.
Since I turned the ignition on before reconnecting a wire on the air intake I had to clear an engine fault code for the air mass sensor.
As it took me 3 hours, I'm not sure I'd do it again but I do like the much whiter light. The OEM bulbs were from Sylvania but the replacements from Philips seem every bit as bright (they are rated the same) and to me a nicer color for seeing things like pedestrians, bikes, road surface etc.