What is the appropriate pigmentation for a stealthy, nocturnal race?

Question

I am building a nocturnal humanoid race for my science-fantasy setting. They are slight, quick, sneaky and very good at being unobtrusive. They are pretty much the goblins of my setting; though not as small as goblins are often depicted or viewed as vermin.

With truth being stranger than fiction, I'd like this race to have realistic skin, eye and hair pigmentation for a nocturnal race. Given that black is actually poor nighttime camouflage, just copying the Drow's obsidian black skin is out.

My initial idea for this race was for their skin color to be a molted swirl of colors that similar was to camouflage-pattern; even if plausible that would still leave hair an eye color in question.

So should the pigmentation for a nocturnal race be?

Answer 1

Just read a book on that called "Animal Weapons." Turns out there's no one best night camo because all nighttimes don't have the same quality of darkness and the ground and background change as well.

They did experiments with mice initially trying to figure out why mice in the same environs came in two different shades, dark and silver. Dark shows up on a white background e.g. sand while silver does not. Silver shows up on black background e.g. soil. Silver shines more in moonlight, and so on.

Sad thing was, they were partially funded by the DoD looking for nighttime camo patterns for deployment to Afghanistan. Trying to save a buck, they rejected the researcher's conclusion to have several different patterns and went with just one pattern to rule them all...until the Special Forces guys came back and punched somebody because their "camo" made them stand out like they had lit flares strapped to the helmets.

So, your Nocturnals would optimally have some kind of chameleon like pigmentation control mechanism so they could alter both tone and pattern as the quality of the dark and the backgrounds changed.

Heres the footnotes for the military camouflage.

• Task Force Devil Combined Arms Assessment Team (Devil CAAT), “The Modern Warrior’s Combat Load, Dismounted Opera- tions in Afghanistan, April–May 2003,” U.S. Army Center for Army Lessons Learned (2013).

• Dugas, K. J. Zupkofska, A. DiChiara, and F. M. Kramer, “Uni- versal Camouflage for the Future Warrior,” U.S. Army Research, Development, and Engineering Command, Natick Soldier Center, Natick, MA 01760 (2004); K. Rock, L.L. Lesher, C. Stewardson, K. Isherwood, and L. Hepfinger, “Photosimulation Camouflage Detec- tion Test,” U.S. Army Natick Soldier Research, Development and Engineering Center, Natick, MA (2009), NATICK/TR-09/021L.

• “New Army Uniform Doesn’t Measure Up,” Mili- tary.com, April 5, 2007; Matthew Cox, “UCP Fares Poorly in Army Camo Test,” Army Times, September 15, 2009.

• U.S. Government Accountability Office, “Warfighter Support: DOD Should Improve Development of Camouflage Uniforms and En- hance Collaboration Among the Services,” Report to Congressional Requesters, September 2012.

Answer 2

You can choose almost any colours you want¹

One would intuitively say that a nocturnal being should have dark colouration of the fur/skin; however, if you look at some of the species at Wikipedia's list of nocturnal animals, then you will notice that while most of them have a darker colouration, several of them does not and, surprisingly, they may even have fairly white parts of their fur.

Choose colour based on environment
The major trend seems to be that the fur is matching the general colouration of their habitat, meaning that they won't stand out from the background neither at night nor at day. Exactly which colours they might have in order to not stand out highly depends on what they are trying to hide from and where they are active. E.g., tree living animals tend to have colours matching that of the bark or the underside of the foliage of their trees, ground living animals often have colours matching that of the light under bushes or near patches of bare dirt (quite few animals are green to match grass or leaves). Then, again, exactly which colours that "becomes a match" for the area they live in depends on the eyesight and colour vision of their predator or prey. As example, the wiki page on nocturnality points out that the reason some lions prefer to hunt at night is because their prey have fairly poor night vision.

And based on whom they interact with
Most mammals seems to have dichromatic vision; that is, they have only two distinct colour receptors which allows them to distinguish ca 10000 different colours (whereas our trichromatic vision allows us to see ca 10 million different colours). Birds, reptiles and amphibians may have tetra- or pentachromatic vision, giving ca 10 respectively 100 times more colours than we can see.

The evolution of colour vision suggests that the reason why most mammals are dichromatic is simply because the first mammalian ancestors were likely were nocturnal and burrowing and therefore did not need to see more colours to survive. Dichromatic vision is described to correspond red-green blindness, which can explain why red foxes does not stand out against the background for their prey - they simply look greenish to the animals they hunt, even though they are clearly red for anyone with trichromatic vision.

So in order to choose colours, you need to think about their lifestyle

Will your species hunt or avoid being hunted by something in particular? If so, what will that creature be able to see and what does the environment look like. If you want them to hunt or avoid an average mammal type of animal, then they get a wider range of colours available. If you, on the other hand, want them to avoid other humanoids with normal colour vision, then you need to make them generally dark with colours that matches their environment.

A quite good way to start finding good colours which matches environments (based on human trichromatic vision) is from the list of military camouflage patterns. However, if you look specifically for night colours, then you will notice that there is only the desert night camouflage listed as night time camouflage. The dedicated page for the desert night camouflage gives the explanation that the camouflage was developed for the night vision devices at that time, those clothes becomes obsolete with current night vision devices. There simply are no dedicated night camouflage clothes nowadays; the military instead use the standard uniforms at night as they still meld with the background and the current improvement is better IR shielding to hide the soldiers. The take-home message here is to select colours which matches the daytime background, as it will be matching the night time background too².

What about the colour of their eyes?

Well, again, that depends. They will likely not have a particularly white sclera, or they will likely have very large irises. Humans are not unique with a white sclera, but most of the other animals which share that trait have an iris which covers most of the visible part of the eye. Regardless if the colour of their eyes comes from the sclera or iris, it is most likely that their eyes are brown, yellow or orange (as those are the most common animal colours); however, you can still choose whichever colour you feel is cool as the eyes likely are adapted to night time and, thus, will have so large pupils that they cover most of the visible part of their eyes while in darkness. They might have essentially only pupils too, but unless they can reduce the pupil size during daytime, then they will be highly troubled (or even entirely blinded) by bright light and likely not be out in the open during daytime.

Should their eyes glow if shone upon?
One thing you might want to consider is if they have tapetum lucidum in their eyes. The tapetum lucidum is a layer in the eyes, located behind the retina. It is highly reflective and is used to improve night vision by reflecting the light which hits the eyes; as the reflection causes the light hits the retina twice, it effectively doubles the available light for the eye. This is also the reason why animals seems to have glowing eyes if you shine a light at them during low light conditions. As an interesting bonus, the tapetum lucidum is different in various animals and therefore give their eyes different colour of the glow effect. Wikipedia lists colours of the glow as

White eyeshine occurs in many fish, especially walleye; blue eyeshine occurs in many mammals such as horses; green eyeshine occurs in mammals such as cats, dogs, and raccoons; and red eyeshine occurs in coyote, rodents, opossums and birds"

The addition of the tapetum lucidum is not really neccesary, you can give other reasons for their good night vision, but it would give an explanation to it and it would give them a cool glow from light sources (which, of course, might be a drawback for them as it can be used to spot them at night).

In short

You can give a range of colours, as the explanation for a specific colour/pattern is highly depending on whom they need to be hiding from.

• If they live on a savannah or in other open areas, then they are likely grey, light brown or beige.

• If they live in forests, then they are likely darker brown, black, darker grey or green.

• If they live in arctic climate, then they are likely white.

• Shapes and patterns might be included if extra camouflage is needed (or if you find it cool).

• Any colour which their prey (or potential predator) cannot see can be worn even if it, to us humans, is a mismatch to the colour of their environment.

• Conversely, they might have other bizarre colouration or patterns if it helps them hide from enemies which can see more wavelengths than we humans can (e.g., IR and/or UV).

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^{1: There are limitations based on which exact range of wavelengths they need to be hidden in. As example, if they need to remain hidden in IR or UV range (for whatever reason - they might need to hide from rocs, which likely can see in the UV range since they are birds), then none of the colours we can see matter, what matters is whether they can absorb/reflect IR or UV. A good example of this is found on Wikipedia, if you look at the figure in lower right corner here, then you can see that the colours of the person in normal light doesn't really matter if one uses IR.
2: Again, if you have any creatures that can detect IR, then you will need to have a colour/material which can camouflage heat, which usually does not influence which colours it has in the visual range.}

Answer 3

It is not like environment changes it's color during nights. Even lions are nocturnal, and stealthy. I would say that similar color to their habitat with possibly bumpy and hairy skin. Not necessarily bumpy, if they move in a forest where the trees are quite straight. To be fast they would not crawl.

Answer 4

Let's have a brief look at what (human) vision actually is.
The eye receives enormous amounts of nerve signals. To actually "see" something, almost all of what is received is truncated. Shapes are isolated from "noise", mostly by contrast, but also by comparison with what the person knows. Exploiting this knowledge, we should find something that has a very poor chance of being recognizable.

Since we are talking nocturnal, you should want darkish colours. You would also benefit from conceiling the shape, which is particularly important and helpful, since a humanoid shape is something the human brain can identify very easily.

So, a darkish, grey-brown tiger or leopard pattern would probably work very well.

Answer 5

From a purely generic camouflage perspective, dark-ish colors like deep greens, browns and greys are best. The real key is the lack of a recognizable pattern. Most predator and prey animals have certain patterns almost hard-coded in. If you see the pattern of 4 legs, 2 horns in a roundish shape, well, that's what you chase. If that pattern gets broken up, with parts of the animal blending with the background, the animal has a harder time discerning what it's looking for.

Humans also use a lot of pattern recognition. I do know that my fluffy black dog in the house is easier not to step on in a dark house, but our tortoiseshell cat nearly gets stepped on , sat on, and otherwise squished on an almost daily basis.

Anyway, pattern breakup is as important as color selection in visually driven animals.

Answer 6

Are these humanoids furry or relatively hairless (like modern humans?). How intelligent are they? How long have they been confined to a specific habitat?

Most intelligent animals have a broad range of environments they are smart enough to adapt to. This would preclude a single optimal color scheme unless the environment is very monotonous across a very large area. The more intelligent the animal, the more likely they are to use materials to camouflage themselves (some lower order animals like insects and fish can also do this). So if they are tool using and can concoct pigmented ointments, they will probably rely more on external camo than natural pigmentation, even more so if they wear clothing and armor.

It seems to be common to have a patterned fur coat than bare skin, and the variety of colors in a fur coat is much broader than what skin pigmentation can achieve, at least in earth mammals. I also suspect that a mottled pattern of skin pigmentation is actually a NEGATIVE trait in mammals, as it signals disease like rashes or infections. So if you want tiger stripes or the like, your race will need to be furry.

Many patterns seen in animals, especially prey species, are not designed to make the animal itself hard to see, but make it confusing to predators when the prey are IN A GROUP. Fish, zebra, etc have this trait. Or the pattern is designed to make estimating the size or exact shape difficult to allow for a last minute escape due to a mistimed attack. This is especially prevalent in open areas where you can't really hide.

But your race seem to be predators. So look towards the big cats for inspiration, perhaps wolves. Prey animals seem to have instinctive reactions towards outlines and specific shapes, so the camo pattern of predators is often designed to break up their profile or blend in while stationary. But they may have visible areas in BACK, so they can be seen by other predators in their group. So your race could have a differential pattern that is hard to see in front, but more obvious from the back. Bright stripes set in contrast to darker areas is great when blending into sunlight streaming through trees, not so much for nighttime.

But it seems like you want a skinned, not furred, race. In this case I'd suggest a brown or grey skin pigmentation that is then augmented with camo paint. Drab earthy colors are pretty much universally good for camouflage and are easily created with skin pigmentation. An olive green could also work, especially if the favored area for this race include lots of evergreen trees with branches close the ground or year round dense green undergrowth. Too dark a tone and you are a negative image when the moon is full. Too light a tone and you "glow" in strong moonlight. They can augment their natural skin tone with leaves, grasses, etc attached to their bodies like ghillie suits and paint their faces and limbs with contrasting colors to break up their outline. Humans are VERY good at recognizing faces, even amidst other patterns, so you definitely want to paint the face if these guys are hunting other humanoids.

Answer 7

Ginger tabby

It's a tried and tested colouration for a nocturnal predator, showing up strongly in the resulting gene pool. The tabby patterning helps to break up the outline against a background. As has already been mentioned, most nocturnal prey don't have colour vision so the fact ginger shows up strongly to us doesn't mean that's true of dichromatic creatures.

Just try not to make them too cute or the whole "vermin" thing isn't going to work out.

Answer 8

Your race should probably be simillar to panthers, or have dark-grey skin, large cat-like eyes, adapted to dark, and very dark and dry hairs.

Answer 9

Pigments have evolutionary power, most animals are coloured because their color is usefull in some way. So actually a nocturnal animal would have any color that is usefull to a nocturnal animal (and we have all varietis of notcurnal animals, some are colored, some are colorless), also keep in mind that producing colors requires some energy.

Utility of a color in animal kingdom:

• Hide from natural predators
• Seduce a partner
• Should warn eventual attackers
• Protect from radiation ( skin)
• Metabolize radiation ( leaves)
• Heath dissipation/conservation

Downsides of color

• Certain predators will find you better
• May be expensive for metabolism to produce the pigment
• Actually the metabolism of the pigment may malfunction causing sickness

Animals that have hiding skin usually have other ways to find partners.

Animals that have very visible skin with drawings usually have other ways to escape predators.

You have to find a animal with similiar position in our animal reign and then give that color to your humanoid. Nocturnal predators? There are plenty of nocturnal predators example in our world, most owls, some mammals, a lot of insects, we have White, Black, Brown, Colored animals.

Give them whatever color you prefer, they live in a forest? than a hide similiar to the one of deers is nice. Do they live in a swamp? Maybe a grey hide.

Or keep the color as last detail, maybe you will find usefull in your plot having a color later, so you keep the "color detail dangling as long as needed".

Answer 10

As the question implies a link between stealth and pigmentation, first I would take a step back and ask why. I see three main reasons you might have in mind:

• Because it's fantasy, and if there's no scientific reason against it you want them to look cool, and make it easy for everyone to remember that these are the stealthy ones.

• Because in your world, they evolved to be well adapted to stealth.

• Because the pigmentation they evolved for other reasons helped them, so they took to a stealthy approach.

The first one is pretty much completely artistic license so I won't delve in to it.

The second: They evolved to be well adapted to stealth. That needs thinking through because it's likely to involve much more than just their pigmentation. What was the evolutionary driver for stealth?

To avoid predators?

What predators?

Do these predators have highly developed senses as you would expect? If so, does your species have all the other attributes to avoid detection? Because a certain colouring alone isn't enough.

What happened to the other intelligent races?

The question suggests that as in most fantasy, this is one of a number of intelligent races. If so, why is this one more stealthy than the others? How did they avoid these predators? If it's geographical, why was this race not simply forced to migrate?

To be better predators?

• What is their prey?
• Why did they need to evolve for stealth when they are intelligent?
• Why did the other races not need to evolve along similar lines?
• Are they physically well adapted for hunting in other ways as well?

The third reason, they evolved this pigmentation for other unspecified reasons, but found it made them well suited to stealth.

• How long have the races of your world been able to make clothing, dye and body paint?
• Do the races of your world not have varying skin colours?
• Does the colour of their skin really give them any significant advantage over another race in this regard?

All things considered I come back to reason one, artistic license. I don't see any convincing evolutionary reason why an intelligent nocturnal race would develop a specific pigmentation. An entire race could only be considered "sneaky" and "stealth" in comparison with others. I imagine it being more of a social response. Goblins are often depicted as diminutive creatures in a violent environment. They adopt this sly sneaky approach being physically outmatched. It's easy to imagine that they would be quite different if surrounded only by weaker creatures who they could bully.

Answer 11

As a sidenote, one thing that is important to remember is that it is not just pigmentation that affects nocturnal camouflage, but also shape and shine.

For example, bare human skin has a shine that can give it away even under ambient light, which is why soldiers' camouflage paint is designed not only to break up the shape of the face (when applied disruptively), but also to matt the skin so that any shine does not give away the shape of the face.

Essentially, what it'd say you are looking for is two principles:

1. It is consistent with the surrounding environment;
2. It is not consistent with itself.

So I'd say an important question would be "what is the nocturnal environment of this race?"

Answer 12

First, WHAT is looking for them?

Their skin will be what it is because of predators, so you must examine what hunts them in the environment. What we see and how we see is different than, say, a jungle cat. And if they are hiding from prey, you'll have to look at the visual system of the prey as well.

In general, skin with a "fade" rather than distinct edges is ideal, rather than one solid color. Look to nature, especially small reptiles.