I've noticed in recent scifi shows/movies such as the Expanse or Star Trek that the lighting inside spaceships have two characteristics:

  • Punishingly blue lighting
  • Dark/dimmed miscellaneous lighting everywhere else

This doesn't seem useful or practical, but it does make me wonder what lighting could we expect in modern or near-future spacecraft?

On the ISS, for example, the space station seems to illuminate a normal, white light in the main hallways or gathering areas. This is done (I presume) for easy maintenance, among other reasons. So darkening your spaceship wouldn't make sense unless you're trying to conserve power.

Also, from my understanding, warm colors are easier on human eyes. Further, blue lighting would require more power than colors such as yellow or red, so why not design spaceships with that sort of lighting?

Better yet, what sort of light bulbs should be used on a modern or near-futuristic spaceship? LEDs? Incandescent? Something else?

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    $\begingroup$ Do you understand the hard-science tag? Most TV shows and movies use lighting for dramatic purposes and not for any scientific purpose at all - how do you expect us to prove that against the hard-science requirement? Maybe Hollywood has produced an official document about it, but I really doubt it. $\endgroup$ – JBH Jul 23 '18 at 23:11
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    $\begingroup$ "Hard-science" for a question which asks why the fictional spacecraft in the abominable ST:D uses bizarre lighting? Why would anybody assume that lamps are wired in series? And "darkening" some parts of the spaceship has clear practical functionality; for example, some members of the crew would very much like to sleep; plus there is are ergonomic rules for the level of illumination of work areas depending on the kind of work being performed -- there is a difference between the illumination in the kitchen and the illumination in a space where people are looking at computer screens. $\endgroup$ – AlexP Jul 23 '18 at 23:11
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    $\begingroup$ @AlexP "for example, some members of the crew would very much like to sleep" you turn off the lights in your room, not in the hallway outside your room. $\endgroup$ – RonJohn Jul 23 '18 at 23:31
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    $\begingroup$ I would strongly suggest the deletion of hard-science, maybe in favour of science-based. "All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc", it'll be quite difficult find that about dramatical effects on light for sci-fi movies. $\endgroup$ – Ender Look Jul 24 '18 at 0:15
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    $\begingroup$ Hard science and science based don't go together. Please pick one. $\endgroup$ – L.Dutch Jul 24 '18 at 4:18


From Wikipedia:

Incandescent bulbs are much less efficient than other types of electric lighting; incandescent bulbs convert less than 5% of the energy they use into visible light, with standard light bulbs averaging about 2.2%. The remaining energy is converted into heat. The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps.

And if you visit the other links in the page you will have (note that there are several values per type due technological advances and quality):

From this list you can see very good candidates:

  • Fluorescent lamps (average light but very durable);
  • Sodium vapour lamp (above average light and quite durable);
  • And LED lamp (very high light and a bit less durable)

However, can you guess which bad property fluorescent and sodium vapour lamps have that LEDs don't have? They have a warmup time:

  • Fluorescent lamps need some seconds of warmup only, but they need an external device (starters) in order to turn on, and that devices need much more maintentance that the lamp itself. Also, they need a "cooldown" time between each cycle otherwise they lose their long lifespan quickly.
  • Sodium vapour lamps need almost 5 minutes of warmup, also they produce some heat.

Even more, both lamps are fragile and can be broken easily with an impact or quick movement from the ship itself.

LEDs lamps don't have these disadvantages. They neither have warm up nor cooldown time. Also, they aren't fragile. They are very small and produce a lot of light. Due to their size, you can store thousands of them together and they won't break.

Color - majority white. Then, other colours.

This is much more difficult to answer.

If you are talking about energy consumption:

enter image description here

It must be red.

If you are talking about psychology you could read this investigation of 134 pages... I won't do that so I've looked at other places.
I'm quite sure someone will disagree with this description about colours, but this was my best attempt searching over the internet:

  • Red: Increase heart beating rate, blood pressure and breathing rate, muscular tension, excitation, and desire, even hunger. It can increase aggressive reactions and comfort.
  • Orange: Increase recreation, mobility, vitality. Estimule breathing and relax. May increase hunger.
  • Yellow: Increase happiness and mood. Increase sight, mental activity, creativity and metabolism. Too much yellow can anger people easily.
  • Green: Its sedative and help to sleep calmly. Decrease blood pressure, beating heart rate and stress.
  • Blue: Decrease impulsivity. Make you more calm, quiet, peaceful and help to wake up. Increase blood pressure, reduce hearting rate and body temperature, and give you a tonic effect. This colour could increase productivity in workplaces.
  • Purple: Increase resistance on muscles and tissues. Decrease sadness and fear but its a melancholic colour (and ambiguous).
  • White: Increase happiness, clarity and produce a cleanness feeling. Also, make places more widen and luminous but also cold and alone.

I would use the different colour for different kinds of rooms.
I would suggest as a "default" colour white because any colour (less white) always makes more difficult to see another colour. Also, spaceships are small, and white colour makes things widen and clean.

  • For bedrooms, I would recommend green or blue, maybe a combination of both (furniture of a colour and lights of another one). EDIT: Orpheus on comment has said it seems that green and blue can difficult sleep because they are also morning colours, even they can produce cardiac problems. So I would recommend instead a colour like white because it doesn't help to sleep, but it makes your bedroom/quarter bigger and cleaner.
  • For passages white, because makes everything bigger and clean.
  • For maintenance, fixing or alert something white, because it makes sight very clear, and in an intense light it keeps anyone awake.
  • For working stations blue and white because it's relaxing and keeps you awake. Maybe blue furniture/machines and white light, so you can see clearly.
  • For night mode are several options:
    • Faint warm orange colour, because even in low quantities you can see something and its resemble dawn on Earth, which psychologically induces calm and sleep.
    • Dark red, because of an effect that I'll discuss below.
  • For nocturnal shift: blue, because it keeps people calm and awake. The absence of blue produces sleep.
  • For failure red because in any moment power (and lights) can shut down.
    The Purkinje effect states that in a low amount of light, our eyes can't distinguish red easily, but blue and green, that is why in low-light environments we can't see bright red, only brights blue and green.
    So in a low-light environment, the red light won't be bright nor annoy your eyes, so it'll be easier for your eyes to adapt to darkness. Higher clarity for us but lower stress for our eyes can be provided with red, even intense.

The insensitivity of rods to long-wavelength light has led to the use of red lights under certain special circumstances – for example, in the control rooms of submarines, in research laboratories, aircraft, or during naked-eye astronomy.
Under conditions where it is desirable to have both the photopic and scotopic systems active, red lights provide a solution. Submarines are well lit to facilitate the vision of the crew members working there, but the control room must be lit differently to allow crew members to read instrument panels yet remain dark adjusted. By using red lights, or wearing red goggles, the cones can receive enough light to provide photopic vision (namely the high-acuity vision required for reading). The rods are not saturated by the bright red light because they are not sensitive to long-wavelength light, so the crew members remain dark adapted. Similarly, airplane cockpits use red lights so pilots can read their instruments and maps while maintaining night vision to see outside the aircraft.

@Joe bloggs commented that lamps should be connected with the central system, so anyone, when they want, can modify the colour or intensity according to their taste. Light could be modified in the control room, using the control panels in each room, or simply with an app on your portable device. Obviously, LED lamps that are able to change their colour are more expensive than normal ones because they are made of 3 LEDs (red, blue and green) but I think the benefits are greater than the cost in this case.

Finally, @user71659 suggested in a comment that LEDs are vulnerable to radiation and high energy particle damage but I don't think it would be a problem because a crewed ship should already be shielded for radiation, otherwise people could get sick. Also, in the future maybe it could be possible to make more resistant LED technology.

Well, like I said it was quite probable that I would receive comments!

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    $\begingroup$ Why only different colours for different rooms? Modern LED technology and control systems let you have pretty much any colour balance/temperature you want at the swipe of an app. Tie that in with the ships control systems and the lights can be another inextricably linked in system that can mess with the holodeck, replicators, deflector dish, reactor core, toile.... $\endgroup$ – Joe Bloggs Jul 24 '18 at 9:52
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    $\begingroup$ I wouldn't suggest using blue and green in sleeping compartments. It can disrupt the circadian rhythm, because blue light is linked to dawn and waking up. After all, there's a reason we have flux. $\endgroup$ – Orphevs Jul 24 '18 at 14:28
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    $\begingroup$ One concern is that LEDs are subject to radiation and high energy particle damage, which may be relevant on your spaceship. $\endgroup$ – user71659 Jul 24 '18 at 14:29
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    $\begingroup$ @EnderLook Yes, I understood that. My point was you are supposed to block blue light for a few hours before going to sleep. I think your mention to the concept of "night mode" is confusing. Blue light is nice for people on "nocturnal shifts". Since there is no night in space, I would just say: blue for people who needs to stay awake, or better yet, for the rooms where people needs to stay awake. I'd also add an "orange" lightning for rooms people use from dinner time to sleep time. (The rest is all great, very nice answer! +1) $\endgroup$ – xDaizu Jul 24 '18 at 15:21
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    $\begingroup$ @Harper: Ah, I see now. Yeah, LED light could look weird for aliens with unusual photoreceptor arrangements. $\endgroup$ – Joe Bloggs Jul 24 '18 at 18:13

Human eyesight under normal light levels (say, cloudless daylight) can receive and process a very wide array of color and contrast. However, where contrast is more important than color, we rely on the Purkinje Effect.

The Purkinje effect (sometimes called the Purkinje shift) is the tendency for the peak luminance sensitivity of the human eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation. The effect is named after the Czech anatomist Jan Evangelista Purkyně.

This effect introduces a difference in color contrast under different levels of illumination. For instance, in bright sunlight, geranium flowers appear bright red against the dull green of their leaves, or adjacent blue flowers, but in the same scene viewed at dusk, the contrast is reversed, with the red petals appearing a dark red or black, and the leaves and blue petals appearing relatively bright.

The sensitivity to light in scotopic vision varies with wavelength, though the perception is essentially black-and-white. The Purkinje shift is the relation between the absorption maximum of rhodopsin, reaching a maximum at about 500 nm, and that of the opsins in the long-wavelength and medium-wavelength cones that dominate in photopic vision, about 555 nm.

Wait... that said blue, why do submarines/airlines/etc use red?

The goal is low-stress/high-clarity. This means lowering the light level, which shifts the eyesight to favor blues (short wavelength colors). But we need to compensate for that, so we use red lights (long wavelength colors). This lowers the stress while maintaining the clarity. From the same source:

Under conditions where it is desirable to have both the photopic and scotopic systems active, red lights provide a solution. Submarines are well lit to facilitate the vision of the crew members working there, but the control room must be lit differently to allow crew members to read instrument panels yet remain dark adjusted. By using red lights, or wearing red goggles, the cones can receive enough light to provide photopic vision (namely the high-acuity vision required for reading). The rods are not saturated by the bright red light because they are not sensitive to long-wavelength light, so the crew members remain dark adapted. Similarly, airplane cockpits use red lights so pilots can read their instruments and maps while maintaining night vision to see outside the aircraft.

But when I watch Star Trek, the lights are blue and bright, what gives?

Generally, blue light is avoided because it causes problems with sleep patterns. However, blue light will be used to illuminate underwater because it transmits a whole lot better underwater than red. Therefore, in cases where people need to see (for example) the ocean floor through a window and their instruments, they'll sometimes use dim blue lighting to see both.

But, does that explain Star Trek?

Nope! Hollywood uses lighting for dramatic effect. It has absolutely nothing to do with reality. They know that red and blue lights are often used in "combat" situations and so they'll use a change of lighting to create the emotional effect for shifting scenes (danger, Will Robinson!). The color isn't that important to them, the change in color is. If they use red it's only due to its recognizability as a "combat mode" color. But you'll see others as well.

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    $\begingroup$ since it's not reallly clear above, the red battle light in subs is so the crew can easily look outside at night (via scope or surfaced). makes zero sense in a space ship. $\endgroup$ – ths Jul 24 '18 at 6:33
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    $\begingroup$ @ths, it isn't clear because it isn't the only reason by a long margin. How do you explain the use of red light by airline pilots, FAA towers, labs, etc? They don't have the problem of the enemy seeing them. The principle reason, as stated, is low stress/clarity of vision per scientific studies. $\endgroup$ – JBH Jul 24 '18 at 15:10
  • $\begingroup$ i never said anything about enemies. its so your eyes can switch easier between indoor and outside night vision. $\endgroup$ – ths Jul 24 '18 at 17:56
  • $\begingroup$ @ths, that's exactly what the second quote explains. $\endgroup$ – JBH Jul 24 '18 at 19:29

Ill answer for modern space craft that actually fly. As for futuristic stuff, the skys the limit.

This NASA presentation has all the answers as to whats used on the ISS

Electro-Magnetic Interference shielded fluorescent lamps, with a corrected color temperature of 4500K are currently used for interior lighting.

Generally speaking spacecraft component design focuses on reliability, weight, and power draw in this case. Incandescent bulbs have a relatively fragile filament making them not so great for intense forces experienced during lift off. They also have a relatively low life span when compared with LED's or Florescent bulbs meaning your gonna need to haul more of them up with you per mission profile.

NASA is exploring LED's and there are plans to bring them to the space station.

The lighting you are talking about is not practical for say, a press photo, or maybe daily work but the ISS is built to do research and if the task calls for soft blue light it may very well be lit that way at any given time.

At night the ISS is actually lit in a green tone.

  • $\begingroup$ another problem with incandescent bulbs is their higher power draw per lumen, and the resulting heat dissipation problems (as all the rest of that power is converted into heat). Don't want something hot enough to cause 2nd degree burns and scorch paper in a spacecraft if you can avoid it. $\endgroup$ – jwenting Jul 24 '18 at 6:39


LEDs are currently the most energy efficient readily available lighting system. Better things may come along, but the reason you read about fluorescent light bulbs in older novels is because they were the most efficient at the time the story was written.

Wait a minute, we have fusion/warp/antimatter/etc. drive, why does power use matter? It doesn't matter much when you are in warp drive and all systems are working 100%. But when your warp core is overloaded and taken offline and your impulse engines have been damaged by enemy fire and your shields are down, you do NOT want to have use any more energy than absolutely necessary for lighting.

LEDs are also more durable than incandescent and fluorescent lights. Some LEDs have glass covers, but that is often for compatibility with the look and/or form factor or older bulb types. But LEDs are themselves solid state devices and do not need to be inside a vacuum or any special gas mixture. That makes them more durable than other types of lighting, which is important when you get hit by phasers.

In addition, LEDs can have multiple-color and dimmable (typically via PWM, but that doesn't matter for your story) capabilities. That allows for:

Sleep vs. Wake Time

Dimming, and possibly some color variation, is great for sleep time on ships. The nice thing about LEDs is you can do all this with one set of fixtures and adjust electronically. Emergency - turn everything on full brightness instantly!

White, most of the time

You want bright, white light for best visibility for reading and working in most cases. Any non-white color will normally make some other colors hard to see. Darkrooms used to use red light because typical film was less sensitive to red light. But for normal use, white light of some variant (cool vs. warm vs. "sunlight") is definitely better than blue or green or red.

There are some exceptions though. In addition to the great theatrical effects, going to red for "red alert" makes a lot of sense. A low red light - enough to safely run to your battle stations - is all you need. The individual consoles will be lit up as needed, but keeping the overall light level relatively low may actually help the crew focus on their tasks instead of looking around at everyone else.


Light color doesn't just effect mood, it also effects visual accuity. I use soft white (probably 2700K) in my home, but 6500K in my shop and outdoor lighting. The 6500K light reveals a lot more detail at the same wattage, particularly when lighting conditions are low. Which is to say, if you want to see a floating hex nut before it smacks you in the noggin', hotter lighting colors are better.

As for color-wheel colors, I would think workspaces and living spaces would have different coloring. But people are weird about that stuff. If I remember correctly, a color study was made to find the LEAST visible color for the F119 Stealth Fighter. It turns out black wasn't it. But fighter pilots "don't fly pastel colored airplanes." was a good enough reason for painting it black.

The commodity value of pigments in space would be quite dear, and safety would be a factor. You sure wouldn't want anything that can spall flake or drip. My expectation is that on a big ship coloring would be handled as a rolled tapes of various widths that could be requisitioned by the shop on a per crewmember basis. So probably coloring would be mostly accomidated by picture borders and the like. Some interior spaces might really end up looking like a picture wall in a resturant or a kindergarden. A total hodgepodge of little things so that people can identify and feel appreciated. As for mood lighting, probably a living and working light frequency would be available in all spaces, with perhaps a voice command for switching between. Adding fancy pleasure cruise colors would probably be an extreme luxury.

I don't think color selection with statistical models is the greatest idea. The people who go nuts, are generally going to be the outliers. So it isn't about finding one "best" color everyone, so much as finding an economical way of accomidating the needs of the all of indevidual crewpersons safely.

  • $\begingroup$ To add to the paint portion: paint is heavy. unless a spacecraft doesnt care about the thrust-weight ratio, things will likely be pigmented their natural state. $\endgroup$ – Stephan Jul 24 '18 at 17:51

You would really want full-spectrum lighting, or daylight bulbs on your space ship, especially if intended for large scale or long term use. You might have people wanting other kinds of lights in specific places, or have alternate lighting for specific scenarios, but there would be a lot that is full-spectrum lighting by default.

Humans are well adapted to sunlight, and for more than just vision - look at lightboxes available for Seasonal Affect Disorder (SAD) or the use of phytotherapy to treat depression. It is also used to regulate sleep cycles in case of disorders. Not to mention the health value of sunlight for Vitamin D production, melatonin synthesis, and some skin disorders like psoriasis.

You are also likely to find full spectrum light useful for food production - light for growing plants, for hydroponics, etc. Not to mention there may well be a purely psychological effect (to go with the physical effects) to having something like sunlight available.

It is possible the full-spectrum lighting will only be available in select areas, for those specific health uses, but it's just as likely that full-spectrum lighting will found in common areas, to best encourage sufficient exposure for most people. And by the time spaceships are quite common, there may be other reasons (known or assumed) to encourage access to sunlight-like lighting.


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