Autoblog and Yahoo may earn commission from links in this article.The LED RevolutionSave for an extremely limited number of choices, LEDs are the norm when it comes to headlights, more so for daytime running lights. It was Audi that started the LED DRL theme way back in 2004 with the A8 W12, while Lexus was the first with LED headlights in 2006 with the fourth-generation LS. Then we get to the original R8 that had both headlights and taillights lit that way. LED illumination is a fine example of the trickle-down effect, as even humdrum compact sedans have these as standard fit these days. Even the cheapest car in America has it.That said, we did notice a seemingly growing issue with LED DRLs. A good number of these have turned yellow over the years. That then begs the question: why does it happen in the first place?AudiWhy it HappensYou've probably seen some Audis and VWs with these discolored DRLs, along with BMWs, Mercedes-Benzes, and Teslas. However, no automaker is immune from this issue, as we've seen yellowing DRLs on many other cars, regardless of size, shape, or body style. From high-end luxury and sports cars to budget-friendly econoboxes, you're bound to see these yellowed or burnt-out LEDs.AdvertisementAdvertisementSo, what causes it? Well, it's all about heat. The modules that run these DRLs can get very hot, and all of that heat trapped inside the headlight housing doesn't help matters. Over time, the acrylic light-conductive tubes degrade, leading to scorching, melting, or turning the DRL yellow. Constantly keeping the DRLs at their brightest setting or high-voltage operation further accelerates wear, as does UV exposure. Of course, the quality of the parts used is also a factor here.But why yellow of all colors? LEDs are actually blue and are coated with a yellow phosphor layer. Again, the heat inside the headlight plays a role here, and as the layer degrades, it shifts the color of the DRLs.Anton Andres/AutoblogCan it be Repaired?Of course it can be repaired, but it also depends on whether it's DIY-able, which in turn depends on the headlight housing in your vehicle, and also your confidence level when it comes to repairing things by yourself. If you catch it early enough, you can restore the DRLs to their former glory. If you're lucky, though, some brands have issued a technical service bulletin to resolve the issue, but in general, there are no recalls issued for these, as these are viewed as a quality or component defect. Should this issue occur during your vehicle's warranty period, it's best to take advantage of it right away.If it's out of warranty, though, it's time to consider a couple of options. You can sand it or buff it by disassembling the affected headlight, and with a small rotary tool or fine sandpaper, you can take off the burnt layer until it's white or clear again. If you're iffy about this method, there are professionals who can do it for you. But if that's still too much work, you can just buy a new circuit board and replace the module completely.AdvertisementAdvertisementUnfortunately, there will be cases where the options mentioned above cannot be done. The headlight housing is either permanently sealed or severely heat-deformed; in that case, the only course of action here is to replace the entire headlight. Obviously, this is the most expensive solution, and buying a new LED headlight can (or, rather, will) put a dent in your bank account. We now live in an age where headlights have circuit boards, but it is what it is.Anton Andres/AutoblogIs There a Way to Prevent it?We wish we could say yes, but it actually depends on headlight design. Some clusters simply trap more heat than others, while for others, it depends on the quality of parts fitted from the factory. Granted, it doesn't affect how the vehicle runs and is more of a cosmetic issue. However, it ages the look of the car quite dramatically, and the uneven fade makes matters worse.As heat is the main culprit here, switching or leaving the headlights in Auto mode for cars equipped with automatic headlights should help prevent it from happening. With reduced voltage being sent through the module, it won't get as hot inside the headlight cluster, slowing down wear and tear. Also, check for moisture seepage in your headlight, as it can contribute to factors leading to discoloration. If it's a manufacturing defect, however, it's really more a matter of when it'll happen than if it'll happen.Once it does, the best course of action is to get it repaired as soon as possible. The earlier you catch it, the better, and it won't be as expensive to fix unless your headlight unit is completely sealed. The good news here is, not all LED DRLs turn yellow as a car ages. If you need proof of that, you can still see many 10- to 15-year-old cars still sporting bright white DRLs even as time goes by.Jeremy Korzeniewski / AutoblogThis story was originally published by Autoblog on Aug 16, 2026, where it first appeared in the Features section. Add Autoblog as a Preferred Source by clicking here.