Tinted headlight bulbs

[Ian.McFetridge@biomeasure.com]

     I have "blue ion" 85W headlights which I bought from Autodesign Haus 
     in Boston.  The lower half of the light bulb is coated with a 
     transparent blue material.  The headlights have a slight blue tint to 
     them, possibly purple.  
     
     At first I only put in one, so that I could see the difference between 
     my stock 55W and the 85W blue ion.  I've noticed that they don't 
     appear to be bright at all from the drivers seat.  I don't know if 
     this is because my eyes are more sensitive to that off-white normal 
     light or because the blue coloring just absorbs a lot of light. 
     
     
     Light colored objects in the road are far more visible with the blue 
     bulbs--white stop lines really stand-out.  However, this may just be a 
     matter of contrast, I've also noticed that I have trouble seeing dark 
     objects--such as the log I almost hit last week.  I think I would have 
     seen that log a lot sooner with normal lights, or if the log had been 
     turned so I could see the light colored core.  
     
     I installed the ion bulbs because I removed my fog lights and needed 
     more light.  The 85W is good, but the blue seems to negate the added 
     power.  In the fog I noticed that my lights refracted less than the 
     people passing me with normal lights--though this may be because my 
     lights were just more dim.  I have driven in a friends 911 with those 
     HID lights and can say the ion bulbs are no where near as bright, 
     white, or evenly dispersed as the HID lights.  
     
     When they burn out I think I will get a normal set of 85W bulbs and 
     maybe put on some dichroic fog lights (I've seen these really shine 
     through the fog and snow).
     
     Any comments on how the wavelength affects the lights.  White light 
     has all the colors of the visible spectrum.  I understand that the 
     problem with fog and snow is that some of the light refracts of the 
     snow before reaching a solid object, is this the long wavelength 
     light?  Why are fog lights usually yellow, that is a fairly long 
     wavelength of the visible spectrum (only reddish is longer).
     
     Does the blue light, being shorter in wavelength (shortest of visible 
     light), penetrate snow/fog better.  I recall hearing that UV light is 
     used somewhere in Europe (Scandinavia?) to allow better visibility in 
     snow/fog.  Since UV is shorter than visible, I assume that blue light 
     is the next best, since it is the shortest visible light.  That is why 
     I don't understand the whole yellow light thing?
     
     Any input?
     
     Ian (Boston, MA)