Is indigo really a color of the rainbow?

I've played Indigo Prophecy, hope that helps.

I agree completely, indigo is bullcrap! I think they added it just so Roy G. Biv would sound right (Roy G. Bv would have been weird).

Yes.

yeah it is...just like all tones shades hues, are colors of the rainbow

No it isn't. The visible spectrum is Red, Orange, Yellow, Green, Blue and Violet. Indigo is technically a shade of violet.

The reason people think Indigo is a separate colour of the rainbow is because Sir Isaac Newton believed that seven was an important cosmic number (seven days in a week, seven musical notes, seven observable objects in the Solar system).

I don't know.

Yes

Maybe, if you look close enough.

Other. I think it once was but is no longer considered one.

According to Roy G. Biv, it is.

No they're not. The rainbow is a manifestation of the visible spectrum and the visible spectrum is linear. The frequency of light is measured in nanometres where a wavelength of 400nm is violet and 700nm is red. A rainbow therefore does not contain much more than 300 individual colours. Shades, colours and hues come from the mixing of the three primary colours of light (red, green and blue). It's how your computer screen works. The intensity of each of the three colours is assigned a value from 0 to 255. This means that it is capable of displaying 256³ colours, which is approximate 16 million (slightly more than a rainbow).You'll certainly struggle to find pink, brown or olive green in rainbow.

I'm not sure. I do enjoy seeing them though.

Never have I heard the color indigo

ok, fine

My hummingbird feeder is currently indigo.

We don't have much capacity for seeing true violet at the edge of a rainbow though. Typically when we see violet, we are looking magenta with a touch of cyan pigment, and our red and blue cones are activated (at both ends of the spectrum). The violet we see is a compound color which, like other mixed colors, exists only in our heads, and not anywhere on a pure spectrum. Six colors is as arbitrary as seven, as really one could argue that 487.273nm and 487.274nm were seperate colors. The relevant reference is of course the receptor wavelength of our cones, which I understand is necessarily broad and sloppy, such that both some of our red and green cone pools respond to yellow light. This system is rather crude though. If we were instead to have more narrow wavelength red and green receptors, along with accurate yellow receptors, we would find that not all yellows are the same, and that a fourth receptor would add an entire dimension to our perceived compound colors, just as red cones add a dimension to green and blue cones.

Hummingbirds are an example of this. All ruby throat hummingbirds look the same to us, green body, red throat, however they have UV markings, and UV cones, so that there are whole 2D spectrums of R-UV and G-UV, or if you rather, a 3D spectrum of RGU which us humans are missing out on.

I always thought that if we were able to see more colors, we would see infrared and ultraviolet, like there was something there we weren't seeing. I never imagined extra colors within the rainbow that we aren't seeing.

> You'll certainly struggle to find
> pink, brown or olive green in rainbow.

Your first hurdle being finding some good acid.

Yep, it's an amazing univese. It occurs to me though that as mushy and vague as our cones are, so too are the produced colors of nature, for instance there is a whole range of greens to be found on dying leaves, and the ability to discern how much of a particular yellowish-green actually was present, rather than chemically intuitively estimated probably wouldn't matter much. Situations with more exacting wavelengths are probably rare. On the other hand, since modern technology opts towards producing exact wavelengths, it means that we could RGBYO computer monitors and discern 256^5 colors instead of just 256^3. Sixteen million colors seems to be plenty enough though. UV and IR would be more useful. Birds can see things like tracks of animal urine which we can't. Theres something to be said though for not seeing things like IR DVD remotes or radio waves, and only translating them to within our sensory range when we want to. I'd hate to have to always listen in on every microwave cell phone call in the city.

The edges of our audio spectrum are interesting too. I have enough difficulty just hearing bass guitar, let alone whale songs, but my high registers are excellent and I think I concern myself with upper guitar harmonics that most others can't even hear, up near 22khz. Not only womens voices, but also their hearing is 150-200hz higher than that of males, which makes it easier for both genders to communicate within their own gender. Telephones were designed by men and favor lower frequencies than if women had designed them.

Coelecanths have a refined sense of electricity. I used to think that was to detect electric eels, but I just found those eels live in rivers. Dolphins have sonar, possibly of a sort to exchange geographic and sculptural data, which puts a sense above us. They can distinguish more complex sculptural forms behind walls than we can distinguish by looking directly at them. They also have muscular control of their sexual anatomy, which makes me question if we really are the most advanced species on our planet. On the other and, we can do things with our hands, so I guess it equals out.

It depends what you mean by 'true' violet. Most people confuse violet the spectral colour with violet the shade. A tin of violet coloured paint is indeed a mixture of blue and red as far as our eyes are concerned. Six colours is as arbitrary as seven, but then assigning categories to the visible spectrum is as arbitrary as any other categorisation of reality - whether it's taxonomy or astronomy. We label this frequency as red and that frequency as green because, as a species, our eyes work in the same way and we can agree on it.
I don't know if it's possible for the frequency of light I see as being red actually looking yellow to a lifeform with a totally different visual system. Similarly, I've often wondered whether creatures that rely on sound to the extent that we as humans rely on light, might not perceive the audible spectrum of sound frequencies in the same way with thumping bass notes a deep crimson and high-pitched chirrups an intense blue.

Some people are said to have such synthesthesia. We really have no proof what goes on in other minds, that anyone at all visualises colors the same. All we know for certain is that they are getting the same signal input to their brain. When you really think about it, it's truly amazing that our phosphor cones translate to what we call vision at all. The only fact of science is three channels of wavelength input. Inside our brains is the only place that red, green, and blue, per se, actually exist. A computer with identical video input might see something entirely different, if anything at all.

Synaesthesia happens when stimulation of a sensory system triggers involuntary activity in another. Because of the way we filter reality through a combination of our senses, that kind of crossover in certain people isn't surprising.

In a sense, we are all synaesthetic albeit mildly so. I've just created a survey to demonstrate this.

I wouldn't call it mildly at all. None of the signals which reach our brains necessarily must translate into any particular form, feel, or sensation.

When we can monitor activity in other brain areas, or have people describe cross-sensory experiences, we have technical synaesthesia, but really, all senses in any form are synaesthesia unless we only perceive a realm of electrochemical neuron firings.

I'm not saying that the way our senses translate the input is not a collaborative process. The way we seem to expect certain nouns to sound based on the visual appearance of the objects they describe certainly shows that. What I'm saying is that what makes it synaesthesia is how it affects the output.

To me, the diagram below shows a random series of 5s with the occasional 2. To someone with actual synaesthesia, the 2s form an obvious triangular shape that they would be spotted immediately.

Well, I'm tripping out on it because it appears to form partial snaking 3D molecular rings all over the place. The 2's just mess up the beautiful-symetry continuity of the curves with jarring breaks of another order - which turns out to be a triangle. Ok, I get what you mean now. I thought you meant each '2' appears as a triangle at first. I don't see the triangle as readily, it's just that they don't fit in with the curves. If I go into triange mode though, I see things the '2's form, and it's then the '5's which don't seem to fit anywhere into the pattern.

Is my description any different than how you naturally view it?

I still don't see how my or any other way of seeing this as connected form has anything to do with synthaesthesia. I naturally think internally in visual maps of symbols, where the symbols (especially colors) typically represent qualitative conceptual information. The color coding of my ToDo spread sheet represents the particular attitude I need to take towards entries. 20 years ago I was trying to create a word processor which gradually changed type faces, italicisation, color, and several other variables on the fly in infinitesimal increments to add several additional channels of meaning to what one was typing. While it's meant to be read intuitively, without analysis, I'd still call that symbolic-metaphor thought, and not actual synthasthesia where one sense was substituted for another. I have though dreamt in sheet music which had many diverse communicative forms, and do have my own system of color coding melodic notation.
If one could call a sense of emottion, or a sense of concept, especially kinematic forms, derived from some other sense, then I'd say I am synthaesthetic. But if one uses that definition, then so is everyone else who gets feelings or visual impressions from music.

I once truly amazed myself, listening to music. Seeing the motion of planets and finding the song is called the motion of planets is not terribly more spectacular than imagining fields of fox hunts with much old music. What got me was picturing a blue electric lady while meditating on some music then finding that that's exactly what Hendrix had called the song.

I love the subtleties that things like nature, music, and painting can evoke. There are some people who consider it to be random meaningless coincidence, but I point out to them that the proof that there is some underlying language to these things is that other sensitive people 'concur' on what impressionist message they got.

Yes, it is.

am I in trouble now?