Red/amber lights in the rear of the vehicle, white lights, in front of it: that is the good old convention and certainly switching their places is a bad idea.

A quick search, however, shows other colors available to purchase. Concerning "to be seen" bicycle lights, should they be avoided?

More specifically, I would like to have one blue light in the front of my bicycle (just because I find it more pleasing), but am I asking for trouble if I replace my white light for the blue light? Would it be a better option to use both?


6 Answers 6


Most places will legally require you to run with white lights on the front and red lights behind. This is crucially important because it immediately tells everybody else on the road whether you're coming towards them or moving away.

I once nearly hit somebody because they had a red light on the front of their bike. I saw that at the usual distance and dismissed it as a low priority, expecting it to be tens of seconds before I reached them and needed to deal with it. Then suddenly they were on me because we were coming towards each other and closing at 40+km/h, rather than moving in the same direction and closing at 5km/h.

Do not use random other colours because you think they look prettier. Vehicle lighting serves a critical safety function. It's not about looking pretty. If you just have a blue light on the front of your bike, that does not say "Everybody pay attention: I am coming towards you!" It just says "I'm probably not very important so deal with the other stuff and come back to me if you have time later to figure out what I am." Blue has the additional disadvantage that human eyes are much less sensitive to blue light than other colours. Blue, especially flashing blue, is reserved for the use of the emergency services in some jurisdictions.

If you want to put additional lights on your bike, standard colours are still better. If legal in your country, use a flashing white and a solid white on the front, or use two solids; ditto with red on the rear. Or put extra lights on your helmet or somewhere on your body. The standard colours convey important information; other colours are just decoration and people don't pay attention to decoration.

  • 9
    Just to show legal requirements change from place to place: in the Netherlands, flashing lights are NOT allowed on a bike
    – Pelle
    Feb 5, 2019 at 14:41
  • 3
    Flashing lights are also not legal on non-emergency vehicles in the USA (although arbitrarily, they're fine if they're on your body). This rule is not widely observed. There's also some research that suggests that flashing lights on bikes are more detrimental than beneficial.
    – Adam Rice
    Feb 5, 2019 at 19:03
  • 3
    Same in Austria. The law requires red rear and white front, both non-flashing lights. Feb 5, 2019 at 19:59
  • 4
    I first saw flashing white lights when I was living in Canada, I find them very annoying, distracting, blinding, in my opinion they should be banned and this ban should be enforced, as they are a danger. I've never seen them in continental Europe.
    – gerrit
    Feb 6, 2019 at 8:08
  • 1
    @gerrit I'd go as far as saying that every LED bike light (i.e., basically every bike light) sold in the UK has at least one flashing mode, so I'm very surprised that you've not seen them in continental Europe. I agree that high-power flashing lights are obnoxious at night. Unfortunately, a lot of people don't seem to understand that the super-bright modes of their bike lights are for use during daylight. Feb 6, 2019 at 10:34

A quick search, however, shows other colors available to purchase. Concerning "to be seen" bicycle lights, should they be avoided?

Yes, they should be avoided.

First, off-colors might not be legal in your area.

Second, and more importantly, no one will know what it is. If a driver sees a flashing red taillight, or what looks like a normal white headlight, that driver is likely to identify you and your bicycle. Something like a blue light is likely to evoke a, "Huh? What's that?" Which means most drivers won't treat you like a known entity - something they need to avoid.

And what do drivers (and cyclists, for that matter) do about things that don't evoke a familiar "must avoid" response? You won't even register as being there. Think about it - how many random items to you ride past all the time? Do any of them really register at all? Trees, mailboxes, plants, fence posts - they don't meet your brain's "must avoid" pattern, so you don't react to them at all.

You do not want to be cycling in the dark where you need lights so you're seen and safe, and then do any thing that makes it harder for others to identify you as a bicyclist.

  • 7
    It's also worth bearing in mind that a driver who's going "Huh? What's that?" at one cyclist isn't paying attention to all the other ones. Feb 5, 2019 at 1:26
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    An anecdote, not about cycling, but it nearly involved me in an accident: I was driving home one night and saw something ahead of me that looked like a huge yellow McDonalds sign, waving about rather like a cartoon ghost. I was still trying to work out what it was when I almost hit it - somebody had decided to make the saddle cloth of their horse "safer" by giving it a high-vis yellow border. If the rider had tied a red light onto his own back, there was some chance it would have looked like a slow moving vehicle to be avoided! ...
    – alephzero
    Feb 5, 2019 at 2:22
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    … with nothing to judge its true size against, I thought I was still 100 yards away from it when I realized the distance was more like 10 feet.
    – alephzero
    Feb 5, 2019 at 2:24
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    @AndrewHenle "Huh? What's that?" is a form of distraction. Distracted drivers, pretty much by definition, aren't paying attention to the stuff they're supposed to be paying attention to. I'm not talking about noticing every little thing beside the road. I'm talking about being distracted by seeing a weird thing in the road and the cognitive load of processing that unusual situation. Feb 5, 2019 at 10:42
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    Because it's mentioned here, as a cyclist and a driver, please don't have a rear light flashing unless you have another that is constantly on. Seriously - flashing lights make it even harder for other road users to determine exactly where you are, much like with the horse in a commend above - this makes you less safe, not more safe. Keep your lights on solidly, please.
    – Baldrickk
    Feb 6, 2019 at 15:11

The topic has been discussed here in the Netherlands, and found an answer summarized in the below chart (text translated into English from the original):

Are you ready for the night? Bicycle lighting hints

Wrapping up: lights should be fitting the standards and fulfill their scope. No blinding, no lighting up in the sky or down the floor, no fancy colors.

  • 7
    I particularly like the comment on coloured headlights: "Use them to decorate your cake" :-).
    – sleske
    Feb 5, 2019 at 9:44
  • I noticed on the bottom image, the cyclist only has one hand on the handlebar. The hand making the sign in-air should be used to decorate the cake, because it is unsafe.
    – dim
    Feb 6, 2019 at 10:22
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    @dim We're expected to signal turns by taking a hand off the bars. Those of us who cyle longer distances regularly take a hand off the bars to take a drink or eat something. Riding one-handed is an important skill when cycling and is perfectly safe when done with appropriate care. Feb 6, 2019 at 10:39
  • @dim Having said that, she does seem to be cyling in high heels... Feb 6, 2019 at 10:39
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    @Ashley, no, you don't want the light of your bike to blind cyclists coming in the opposite directions because they are pointing too high
    – L.Dutch
    Feb 8, 2019 at 12:51

Depending on where you are in the world, there may be legal requirements.

For example here in New Zealand at night time you MUST have

  • White light on the front, no more than two, only one may flash, must not dazzle other road users. Must be visible from 200 metres.
  • Red light facing the rear. Must not dazzle. Must be visible from 200 metres
  • Pedal retroreflectors both front and back. If the pedal doesn't have this then the rider must be wearing reflective material.

At ANY TIME you MUST have

  • Red or yellow rear reflector visible from 200 metres when illuminated. Yes, even in daylight.

You MAY have

  • High visibility vest
  • Additional amber/yellow point lighting (ie be-seen lights, not for illumination)
  • Yellow, Orange, White or Amber side reflectors on wheels with a certain minimum area and reflective angle.

You MUST NOT have

  • Blue lights of any variation - this colour is reserved for police vehicles only
  • Green lights of any variation - this is reserved for private vehicles on emergency medical work (think doctors going to emergency surgery )
  • Red lights pointing forward
  • White lights pointing backward

From https://www.nzta.govt.nz/resources/roadcode/cyclist-code/about-equipment/cycle-equipment/#compulsory

My personal bikes tend to have more rear lights because of the roads I commute on.

And to complement your question - is the wrong light better or worse than no light? I really don't know there.

  • 2
    Yes in some jurisdictions a blue light is not only not-legal (i.e. is not the light which you're required to have), but it's also illegal (i.e. is impersonating a police vehicle).
    – ChrisW
    Feb 5, 2019 at 14:38
  • 1
    Is that rear reflector size "175 square millimeters" or "175 millimeters square"? There's a huge difference: 175 square millimeters is a tiny spot that I doubt I'd be able to see in time to avoid hitting you, while 175 millimeters square is a huge reflective patch that I'd be able to see well in advance -- and probably before I'd be able to see your rear light.
    – Mark
    Feb 5, 2019 at 21:03
  • @mark nzta.govt.nz/resources/roadcode/cyclist-code/about-equipment/… has the proper list - updating answer now.
    – Criggie
    Feb 5, 2019 at 21:05
  • @mark goes to show one shouldn't rely on memory. All fixed.
    – Criggie
    Feb 5, 2019 at 21:11
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    If it's a "warm white" yellow, then that should be fine (I'm specifically thinking of old incandescent bulbs here, or LEDs that emit a warm light). Likewise, a "cool white" light (majority of LEDs) isn't blue. If it can be more accurately described as "amber" (colour designation here) then don't use it unless it actually is an indicator light (though I don't find that the ones you can get for bikes are much good)
    – Baldrickk
    Feb 6, 2019 at 15:19

This question has two parts : is it wise to change the colors of your lights ? and is it legal to do so ?

Concerning whether, regardless of the law, you could change the color of your lights, I'd say it heavily depends on which color you choose, and in which country you live.

Lights have to purposes: to see correctly the road and to be seen correctly. - Concerning the first part, in some conditions, having some lights that are not the usual ones can have some benefits. In particular, I'm thinking about having a yellow front light (instead of a white one). A yellow light is less blazzing than a white one, in particular in the fog. This is actually why, in France, from the late 30's till 1993, only yellow front lights were allowed [1]. As of today, they are still allowed, but tend to disappear nontheless, except on old bike where they are still pretty common. However, if, for instance, you put a dark blue front light, then it is almost useless. - Concerning the "to be seen" part [2], some people argue that having a blinking light (front and rear) is more likely to attract the eye of other drivers, hence you'd be noticed from a further distance. This arguments has two drawbacks, however: (1) even if you notice blinking lights from a greater distance, it is much harder to evaluate if this light comes closer to you or go away. This can be a trouble if you have a red blinking front light for instance. (2) This doesn't scale. You can distinguish a single blinking light from far away, but say you have 10 blinking lights, out of sync. You can not precisely tell how many people are there.

Finally, remember that lights are not here to be fun, they are here for the two purposes above, hence you should always respect the conventions of the community. These are what people expect other people to do. If you put red and green lights on the side of you bike (like boats or plane), people won't understand what you're doing.

On the legal side, this heavily depends on the country you live in. It would be smart that everybody expose his local laws.

For France, all you need is in the Code de la Route, Partie reglementaire, Livre III : Le véhicule, Chapitre III: Éclairage et signalisations, Section 1 : Éclairage et signalisation des véhicules. It's all available (in french) here

The first article (R313-1) is actually the most important with respect to your question which basically says that except the lights described after, you can not put any lights.

Tout véhicule ne peut être pourvu que des dispositifs d'éclairage ou de signalisation prévus au présent code. Ceux-ci doivent être installés conformément aux prescriptions du présent chapitre.

Ces dispositions ne concernent pas l'éclairage intérieur des véhicules sous réserve qu'il ne soit pas gênant pour les autres conducteurs.

Le fait, pour tout conducteur d'un véhicule à moteur ou à traction animale, de contrevenir aux dispositions du présent article est puni de l'amende prévue pour les contraventions de la troisième classe.

Le fait, pour tout conducteur d'un cycle, de contrevenir aux dispositions du présent article est puni de l'amende prévue pour les contraventions de la première classe.

(Traduction and emphasis mine)

Any vehicle can only be equipped with the light or sound equipment provided in the following regulation. They have to be installed according to the specifications of this chapter.

These rules are not about the inner lighting of the vehicle, provided that it is not disturbing for other drivers

The fact, for any driver of a motor or animal powered vehicle, to breach this article is punished of a fine for 3rd class infractions.

The fact, for any driver of a cycle, to breach this article is punished of a fine for 1st class infractions.

Notice that, as a cyclist, your ticket will be much lower than for cars (up to 38€ vs up to 450€).

The lights you are supposed to have are described in the following, in particular in the R313-4 (front light) and R313-5 (back light)

... X.-La nuit, ou le jour lorsque la visibilité est insuffisante, tout cycle doit être muni d'un feu de position émettant vers l'avant une lumière non éblouissante, jaune ou blanche. ... XIII.-Le fait pour tout conducteur d'un cycle de contrevenir aux dispositions du présent article est puni de l'amende prévue pour les contraventions de la première classe.

... X.-The night, or the day when the visibility is not sufficient, any cycle should be equiped of a position light emitting toward the front a non-blazzing light, yellow or white. ... XIII.-The fact, for any driver of a cycle to breach this aricle is punished of a fine for 1st class infraction

and for the rear one

... V.-La nuit, ou le jour lorsque la visibilité est insuffisante, tout cycle doit être muni d'un feu de position arrière. Ce feu doit être nettement visible de l'arrière lorsque le véhicule est monté. ... XI.-Le fait, pour tout conducteur d'un cycle, de contrevenir aux dispositions du présent article est puni de l'amende prévue pour les contraventions de la première classe.

... V.-The night, or the day when the visibility is not sufficient, any cycle should be equiped of a rear position light. This light should be clearly visible from the rear when the cycle is ridden ... XI.-The fact, for any driver of a cycle, to breach this article is punished of a fine for 1st class infraction.

(I actually just noticed that it is not required that the rear light is red, which is for motor vehicle).

Finally, notice that you have other obligations regarding lights, in particular for reflectors.

[1] Notice that the introduction of yellow lights corresponds to the begining of the 2WW, hence the widely spread (and wrong) belief that yellow lights were introduce to distinguish french cars from foreign cars in the night. More info on wikipedia (french).

[2] I don't have any link to any serious study, but the argument still makes sense. If you have some, please comment.

  • 3
    It's spacecraft, not bicycles, but part of the reason the Gemini 4 rendezvous attempt failed is that the target vehicle had a blinking light, which made it very difficult to judge the target's position and motion.
    – Mark
    Feb 5, 2019 at 21:10
  • As an aside, at what time (in France) must lights be switched on -- e.g. is it at sunset, or is it a half-an-hour before or after sunset, or is it when it's dark enough? Or is it whenever the streetlights are switched on (if that's a standard time), or is that based on "when it's dark enough" too and not a specific time?
    – ChrisW
    Feb 6, 2019 at 10:30
  • @ChrisW This is not specified in the law. I'd say it is "when it's dark enough". Basically, when it's dark, you have to turn your lights on, based on the "when the visibility is not sufficient" part, for instance in tunnels or during an eclipse (even tho during an eclipse, you should probably stop a profit of the spectacle). So even if there is no official hour, an officier can always tell you to turn your lights on based on the low visibility.
    – Bromind
    Feb 6, 2019 at 11:11
  • 1
    Nevermind getting fined, worry that you'll give drivers an excuse if they hit you and you weren't 100% compliant with the law. Feb 7, 2019 at 8:25

As long as you have primary rear red and front white, you can probably add in some other smaller lights of different colors - as long as your local laws allow it.

I’ve seen riders running rear lights with blue or orange in addition to red on my local trails.

I’ve also seen secondary orange front lights.

  • 2
    Trails may have different rules than streets, and just because you've seen someone do it doesn't make it legal -- or smart.
    – Mark
    Feb 5, 2019 at 21:11
  • To be clear the lights I’ve seen people using are all off the shelf commercially available items Feb 5, 2019 at 22:04
  • 3
    That they are "off the shelf commercially available items" does not make them legal bike lights. And I can tell you, the vast majority of lights I see on other peoples bikes is most certainly not legal, or not fixed in a legal way, or illegally covered by a backpack, long coat or luggage, or ... People generally don't care about the legality of their lights, and they don't even realize how much they put themselves at danger by not caring for that. Feb 6, 2019 at 23:47

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