xtwinkiieex: First of all, Projectors and HID have nothing to do with each other. Projectors is one type of headlight, which is better for HID use than Reflectors. Still you can have either HID or Halogens on either kind of headlight. All ISx50 have Projector type Headlights.
Now you need to figure out if you have HIDs or not. To do so, just look at the lights when you turn them ON (you can have someone to look or you look while someone turns them ON or go close to a wall and do it all yourself while looking at the wall). When you turn ON HIDs, they have a very small flick like a neon light. That is the igniter turning them ON.
You also will know if you have them as the ISx50 have the auto level feature only for the HID (the projector inside the headlight moves to adjust the direction they point to help on turns, etc).
If you have HIDs, then you probably want to upgrade to a higher color temperature to obtain more blue out of the light. I wouldn’t go with anything higher than 5000K as the blue color will make your eyes get tire faster and will also start going down on brightness. Anything higher is more for show and could get you also in trouble with the police as it could be illegal in some places. Besides that, if you have fog or lots of rain where you live, you are better off using stock color which is around 4300K. The stock or OEM HID bulbs are D4S.
If you don’t have HIDs, then you need a conversion kit. There are plenty on the market. I just got a week ago mine from Xenon Depot. Everybody have good things to say about them, and so do I. Customer service is A+ and delivery was as fast as it could be. The kit is easy to install and should take only 2 to 4 hours depending on how good you are with tools under the hood. The stock or OEM bulbs for Halogen are H11 and you need to order a kit that has those bulbs so they can fit in the socket.
kingofthievez: just read above.
Original Fake: I just got my kit from Xenon Depot. They are having a special. If you look under their section on the Forums, they have a link for the special. You save $25 (about the shipping cost). I got it in a week after I order it. the price would be around $225.
They have many different colors, just go to their page. Andn o, you do not get D4S bulbs. You must order the H11 conversion kit so you can “plug & play” the bulbs in the stock sockets which are H11 type.
Read above for more info.