you guys really need to be careful when ordering a set of HID replacements.there's alot of s*** floating around the internet like alot of the stuff you'll find on ebay. alot of the cheap korean knockoffs you have to actually drill the base of the buld so it can be fitted securly into your car. not something alot of people are going to want to do but if they can save a couple hundred of the allmighty bucks they do it. check these links and you'll get alot of great info like i've found.
http://www.intellexual.net/hid.htm
http://faq.auto.light.tripod.com/headlight-menu1.htm
Yellow:
1500 k Candlelight
2700-2900 k Yellow painted fog halogen bulbs
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Yellowish white:
3200 k Sunrise/sunset
3200 k Premium H7 non painted halogen bulb
3400 k 1 hour from dusk/dawn
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White:
4100 k Philips/Osram OEM HID D2S
5500 k Bright sunny daylight around noon
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Blueish white
5500-5600 k Electronic photo flash
6000 k Philips Ultinon HID D2S
6500-7500 k Overcast sky
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Blue:
9000-12000 k Blue sky
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Purple:
28000 Northern sky
12000-30000 k Ultra Violet light (black light)
a couple of the most important things to remember is that Philips and Osram are the main manufacturers of factory HID's so odds are if you find somebody offering "PHILIPS HID's" then they're probably just the ballasts so don't fall for it. another is the kelvin rating on the lights. the higer you go the more blueish-purple they tend to get. whether it be different gases inside the bulbs or some kind of tint on them they become more useless as well. this explains why i went with the 4500K RISING WHITE. its about the purest white color you can get.