Output for HIDs in most halogen headlights is not going to look right at all. For most halogen bulbs, the filament of the bulb is oriented sideways where as the HID light arcs top to bottom. This means that only 1 small spot does the light actualy line up. The optics on normal headlight are usualy designed to take advantage of this sideways spread, so instead when you put on the HIDs, your throwing light at an angle it wasn't intended. Now that is more of an issue with reflector based headlights than projectors, but it applies to both since optics are very sensative in this respect. On top of that, there is also the manufacturing of the bulbs aswell. Some rebased HIDs don't even line up the optics properly and is way off, or they have the return wire running down the wrong spot and it casts a shadow. It's real hit or miss with these kits but for the price, its worth the risk soemtimes.
On to color output. I posted here what i had from another thread. It has 2 real good pictures of typical color output of the bulbs. As a rule of thumb, the higher the kelvin, the less distance your going to get on your output with the peak being right around 5800K (give or take a few hundred)
[SMAN] wrote:The thing is that at that brightness, it's going to look very blue next to other cars. If your looking to have the HID look without standing out (and being a cop magnet too), go with the OEM 4300, or perhaps a 4800 or 5300. Over at HID planet, i'm sure you can find color comparison pics (infact wasnt there one posted here?) There was,
http://solaraguy.com/viewtopic.php?t=39711, but if you look at places like hte hidplanet.com forum, you can find pictures like this

or my personal favorite

I hope this helps in your decision making process.