[pct-l] Hiking Colors

[rbelshee at hotmail.com (Rod Belshee)]

Regarding the question of which is the most visible color...this is a fun 
topic. There are several elements that interact in interesting ways...

Human eye:

In daylight, the cone-vision of the human eye is most sensitive to 
yellow-green. That is, it has a higher response to a given amount of 
yellow-green radiation than the same amount of radiation of other 
wavelengths. The eye responds to all colors from reds through blue-violets, 
although diminished at each end of the spectrum.

At night, the response curve peak for rod-vision shifts a bit further away 
from yellow to pure green, and the range narrows sharply. In particular the 
reds virtually disappear (a red apple may appear black while a green one is 
still quite light gray).

The object:

Generally objects produce a color by reflecting some colors of light and 
absorbing others. We see what is reflected. A white object reflects most 
everything, a black object absorbs most everything. A very pure green object 
in white light reflects the greens and absorbed the red-orange-yellow, and 
blue-violet. A pale green objects reflects most of the greens, plus some of 
the rest of the colors.

The light:

The color of the light matters because the object is just reflecting or 
absorbing the colors that shine on it. In a pure red light, an a red apple 
is red and a green one black. In a pure green light, the red apple is black 
and the green one is green. Early and late daylight has more reds and less 
blues (the blues are more readily absorbed in the atmosphere, and the low 
angle sun causes the light to travel through more air). The color of 
lighting is significant indoors or in photography, but less so for hiking.

Flourescent:

It gets a bit trickier when we add in flourescent colors. That is neat 
trick. An object absorbs wavelengths of one color and then emits it as a 
different wavelength, say yellow or dayglow orange. That is how some things 
seem so incredibly bright --if you measured it you would find there is more 
orange reflected off the object that shown on it in the first place! Cool 
trick.

Visual perception:

Combining this together, what is the brightest color? Well, strictly 
speaking it is white --that means that all of the light is reflected back 
and seen, so it is brightest.

Think of vision as consisting of three components: brightness, color, and 
saturation. The brightness is the total amount reponse to all of the light, 
the color is the predominate wavelength of the light, and the saturations is 
the purity of that color. For example, the bright pure green object is 
highly saturated (the object absorbed everything except green) and a muddy 
green object is poorly saturated (other colors are reflected with the 
green).

So, what's the brightest color for hiking gear?
- of course, white if the brightest color and black the darkest.

Within colored objects, what are brightest?
- during the day, a light yellow-green pack or jacket will appear brighter 
than other colored objects,
- at night, a light green tent is easier to find, while reds are very dark,
- but the brightest of all are the flourescent day-glow yellows and oranges.

Most visible:

Then there is the question of most visible, meaning easiest to distinguish 
from the background. In the lush northwest coastal forests, a green jacket 
will dissappear because it is the same color as everything else. A dark tent 
might be easier to find on a brightly lit night in the open on light-colored 
rocks.

The human retina heightens the difference between opposite colors. Generally 
you can look at opposites more vvisible: wear red in the green northwest 
forests, wear green on the red rocks, wear blue in the partched yellow 
sands, wear yellow on blue water. Again, the eye is more sensitive to some 
colors than others, so in a dark green forest, the red can be enhanced by 
shifting a bit closer to the middle of the spectrum such as orange.

And of course patterns also play a role, hence the camo patterns which 
combine shapes of various shades of background color.

Even more important is motion, since the eye responds extremely well to 
motion. If you want to hide from an animal, first and foremost FREEZE even 
in out in the open. Also deny the animal patterns that it is very adepts at 
picking out, such as eyes. If you want to find your tent at night, tie your 
bandana on it to flop in the breeze (even better you might hear it!).

And then there is culture. In most cultures we learn to respond quickly to 
red and less to blue (even if the strength of reponse from the eye is 
equivalent), and perhaps there is even hard wiring in the visual cortex that 
cuases this.

Of course we can also complicate this by talking about the relative merit of 
blue automobile headlights versus white, but that brings up a whole bunch of 
other issues, which are not trail related...

There, is all clear now?

As you can see, there are factoids that can be used to back up most any 
argument anyone would want to make.

For visible colors, you can argue which color the eye is most responsive to 
during the day (yellow-green) or during the night (green), which are 
brighter (white), which stand out from the trail environment best (all 
depends: maybe reds or blues), which are conditioned to reponded (red), or 
add in tricksters (flourescent yellows and oranges).

Or to be less visible, you can argue for colors that are not bright (black), 
not bright at night (red, violet), culturally unresponsive (blue), or blend 
into the trail environment (all depends: maybe greens/grays/beige).

So just pick your favorite color and then argue that that one is the best! 
CYOH!

Steady Sr.