to do a hid conversion, the most accurate way is to retrofit highend car projectors into your factory projectors or aftermarket projectors

parts for an hid conversion includes
hid ballast x2

hid ignitor x2 some ballast might have this built in

hid bulbs x2 - 4100k for yellower look 4500k for factory white and 6000k for ultrons anything over 6000k, the hid becomes inefficent, since most human eyes cannot see most of the llight after 6k

hid projectors x2 - some people use h7 projectors because it produce a similar beam pattern, one of the most popular projector is the s2000 projector because its small and compact, which lead to it's ability to be fitted into most projectors, i personally have valeo h7 with hid base plates. becareful on choosing an h7 projectors too, not all of them will get the results you want

a few misconceptions:
the blue and purple on most cars are not the color of the bulb, the bulb infact release white light, and the projector's cut off portion spreads the light like a prizm, which gives that multicolor effect while going over speed bumps

those blue bulbs are nothing other than regular halogen with a blue film over it, which filters out the yellow in the bulb, the disadvantage of that is less usable light will be on the groud, making the ground dimmer, try to see next time you are on a wet road, notice it's much more difficult. some manufactures of "fake hid" raise the voltage on the bulb to produce more light, which release more heat and often melt wires around it

hid actually produce less heat than standard halogen bulbs, and use about 35 watts to produce the lights

i think that's about it, correct me if i made a mistake, thanks