Why Are JDM Fog Lights Yellow?

Here at Garage Dreams we are big fans of JDM cars.

In fact, we have written a number of articles on the topic, our most popular being a comprehensive guide to the meaning of JDM (read it here).

We are on a quest with our Car Facts series to answer as many JDM-related questions as we can find people asking online.

In this article we are picking apart a particular question we have seen a few people ask online, which is “why are JDM fog lights yellow”?

You might have noticed that lots of JDM cars feature yellow lights that sit below or to the side of the regular “main beam” headlights:

Let’s take a closer look at why many fog lights on JDM cars are yellow/amber in colour.

Please note that for this article we are referring specifically to front fog lights, not rear fog lights, which are red in colour.

What Are Fog Lights?

To make sure we are all on the same page, this is a quick reminder that fog lights are auxiliary lights fitted to your car to make driving easier in foggy conditions.

The beam of light coming from a fog light is meant to sit low and shine downwards, illuminating the road in front of the car instead of lighting up the fog that sits above the road (when you use your high beam headlights in the fog, this difference in light beam placement/positioning is why the light will often reflect back and create possibly dangerous glare – it is a mistake to try to use high beams in fog as this doesn’t improve your vision or your visibility, and instead could dazzle yourself or other road users).

In very simple terms, fog lights cut under the fog and make short-distance visibility much better, decreasing the likelihood that you will rear end another car or miss a corner.

Not all cars have fog lights (in fact, fog lights are becoming increasingly less common on new cars, as automakers believe that advances in lighting technology are rendering fog lights irrelevant and unnecessary).

Sometimes fog lights are a trim/model level option, or they might be an optional accessory a new car buyer added on when purchasing the car.

It is also sometimes possible to add on fog lights as an aftermarket option, although if you are interested in doing this you’ll want to check the regulations and rules in your jurisdiction as what is acceptable in terms of fog lights differs from country to country.

Why Are JDM Fogs Yellow?

Some people incorrectly believe that JDM fog lights are yellow for purely aesthetic reasons (people tend to either love or hate the yellow light look).

For example, how good does this R34 GTR look with yellow fog lights? (Read our article here on why the Nissan Skyline is illegal in the United States for more information about this legendary car)

However, the real reason is to do with making fog lights more effective.

Long story short, yellow fog lights improve drivers’ vision in foggy conditions, heavy rain or snow, when compared to white fog lights.

As you might recall from school science class, visible light is made up of a spectrum of colours.

If you shoot a beam of light through a prism, you get the cover art to Pink Floyd’s Dark Side of the Moon album:

What is important to understand here is that not all light colours are processed in the same way by the eye.

The colours with shorter wavelengths (blue indigo and violet) are harder for the eyes to process correctly.

When you see something reflected back at you in blue light, it appears fuzzy because of how the eyes process this light.

With that blue light removed, everything has a yellowish tinge which is easier for the eye to process and does not have the same tendency to cause glare.

This is why fog lights – including JDM ones – have historically been yellow.

When you illuminate the area in front of your car with a yellow fog light, that light is not going to cause as many problems in terms of pushing glare back at your eyes, making the driving process easier and less stressful.

In fact, there is actually a name for this specific yellow colour – “Selective Yellow” (you can read more about the science behind Selective Yellow on Wikipedia).

In some countries – such as France – all headlights were required to be this colour up until relatively recently.

Are All JDM Fog Lights Yellow?

No, there are plenty of JDM cars that have white fog lights, especially more recent cars such as this Toyota Crown – read our Toyota Crown buyer’s guide here.

Not all shades of yellow are created equally either.

For example, here is an image of the fog lights from a 2009 Subaru Legacy that was a JDM model imported into New Zealand (this is one of the Garage Dreams editors’ cars).

 

You can see there is a yellow tinge to the light but it clearly isn’t as strong as “Selective Yellow”.

There is definitely a yellowish tinge but not to the same extent as some cars:

Ultimately, white and “lesser shades of yellow” fog lights can still do the job required of them as the issue is more about the placement of the lights and the direction of the light beam, but if you can deal with the aesthetic issue (and we reckon that Selective Yellow fog lights look good anyway) then you are probably better off with yellow.

Recap – Why Are Fog Lights On JDM Cars Yellow?

JDM fog lights (and sometimes those on other cars, especially older ones) are yellow/amber in colour because the yellow light is meant to cut through the fog better and reduce glare, making driving easier and safer in foggy conditions.

Whether or not yellow fog lights cut through fog better is a topic that is still debated to this day.

However, the consensus does seem to be that yellow is a superior light colour for visibility in foggy conditions (as well as heavy rain or snow) because of the reduction in glare and the fact that it is easier on the eyes of the car’s driver – people driving in foggy conditions with yellow fog lights tend to report their driving experience as being less stressful than those with white fog lights, which might look superior from an aesthetic perspective but aren’t as good at reducing glare and improving visibility in inclement conditions.

Some owners of JDM cars like to fit aftermarket yellow fog lights (or yellow bulbs to existing white lights) in order

What is your view on yellow fog lights? Do you think that yellow makes much of a difference when driving in fog? Do you think that it is more of a visual/aesthetic upgrade than anything practical?

Let us know in the comments section below.

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