Question about tail lights on a car and light bulb.

um… Red + blue = purple ?

A shade of purple, depending on the opacity of the bulb filter and the cover filter.

is it illegal to have PURPLE Tail/Break lights in the state of California?....lol im sure its illlegal/. haha but just wonderin.

safety would be my concern. I would want my break lights very visible not dark. Its your rear end.

Actually, I don’t think you’ll end up with purple. You would get purple if you combine a blue light source with a red light source; that’s an additive process. But that’s not what’s happening in this scenario. Here you’re taking a blue light source and passing it through a red filter, a subtractive process. The red filter will only allow the red wavelengths to pass, no matter what the color of the light source. A blue light source will produce little to no red wavelengths. If both the blue source and the red filter are the actual primary colors, then no light will pass through. If the “blue” light actually has a purplish cast, then it will appear dimly red through the filter.

Here is a good online demonstration of how spectral filtering works. If you drag the colored disks (which represent filters) over the various scenes (which represent light of various wavelengths), you’ll see the effect of the filter. Try viewing the blue scene through the red filter and see what you get. That’s the equivalent of your taillight scenario.

From the State of Oregon:
“Oregon has adopted the Federal Motor Vehicle Safety Standard 108 for lighting equipment. The standard is very specific for tail/brake light lenses and front side marker light lenses. The standard requires red lenses (not red bulbs) for the tail/brake lights and red rear and side reflex reflectors and red side marker lights. A separate rear side marker light and reflex reflector may also be allowed for the rear lighting system to meet the standard. The front side marker lens lights can be either white or amber (yellow) and must also have an amber (yellow) reflex reflector incorporated into the lens or have a separate side marker light and reflex reflector to meet the standard. So, the answer to the question is in most cases after-market (non-original equipment) “Altezza” or European tail/brake and front marker light lenses are NOT legal for street use in Oregon. They usually lack the required reflex reflectors and side marker lights. Here is a link to a Web site with more information. http://fmvss108.tripod.com Note the “Recalls” section. Most all of the after-market “Altezza” and European lenses have been recalled for not meeting FMVSS 108. (ORS 816.010).”

I suspect most other states have adopted the Federal standard as well.

i agree with harp. this has more to do with refraction index than mixing colors.

okay there making tail light bulbs with LED’s in RED, WHITE, BLUE , i would really like GREEN. or BLUE. from what iv seen it comes OUT REALLY BRiGHT PURPELISH RED…but again the tail lights have shutterd CLEAR AND RED LENSE….but tinted black kinda…lol but again kinda this is what my tail lights look like: http://thumbs.1aauto.com/LTL/1ALTL00016.jpg except the top orange is Actully Clearish reddish orange..lol kinda funky psy. ok i dont really understand if i put BLUE LED with 100 LUMENS LED it will be a DIM red? thats empossible….concedering the LUMENS emttings from the 32 LED’s…..yea its blue but blue and red make pruple as u stated…..but with SHades of striped clear / red makes blue red? right?......grr im confused now. haha

Let me put it another way. You would get purple if the red lens were adding red to the blue light from the LED. But the lens doesn’t add anything. What it does is to take away whatever isn’t red from the light that goes through it. If that LED is putting out only blue, and if the red lens is only letting red through, then nothing gets through, no matter how bright that blue light is.

OK, that’s the theory. In the real world, there may be a bit of red mixed in with the blue light of the LED. If there is, then that will get through the lens. Also, the filtering effect of the lens may not be entirely efficient and it may allow some other wavelengths besides red to pass. The more intensely red the lens is, the better it will be at blocking other colors. But the fact remains that large amounts of the blue light will never make it through the lens, so you’re bound to lose a lot of those 100 lumens.

far as im concernd with my car and its so called “Standerds” can kiss my butt. im gunna try the blue led bulbs take a pic n show ya’ll if thats cool, so will c if i get pulled over or not..heh a fix it ticket is no biggie. :) thanks all for the commenst totaly answerd muh questions eh!

The specs for tail light bulbs are probably around 55 or 45w/12v. If you install the “blue diamond” lights or whatever it is that you posses, it will most likely be 80w/12v. Harp has made a great point. Even though they are tinted black, it will probably will have a fluorescent red to it, bright fluorescent red.

wow, i went in got 32 led “Neon Green” bulbs and shit there a reddish/purple/bluesh green colour amazing and hanvent been pulled over yet. even had so far 4 chp on free way behind me and about 6 city cops non did a damn thing ..lol thanks for the comments and answers all. ‘some thing’s you have to just do your self without Questions”

I have a red tail light lens, but i have an amber LED bulb. is that illegal on a motorcycle in California?

as long is it doesn’t shine BLUE/PURPLE while hitting the brake light.