The colour purple

[JacksSmirkingRevenge]

So why is there no wavelength assigned to it?

[Cormac]

I once brought 2 large coffee mugs
of the most divine and regal purple. The first time I used them to serve a hit beverage to Husband Dearest he was taken with their beauty and exclaimed
"Nice blue mugs!!!"
I smiled gently and giggled to myself,
And ever so gently pointed out what was as clear as day
"They are purple, Husband Dearest, not blue"
" you nuts?" He replied. " they're blue"
" purple!"
"Blue"
And so it began. We would pull the mugs out when we had visitors and adjectives them"purple or blue?"
People stopped visiting. The children refused to even look at the beautiful Purple mugs.
And then one magic day it happened. While I was watching the television box, an advertisement came on for a Magic Machine.
"Looking for just the right shade of paint? Got something in the right color but can't match it? Well bring that thing down to us at the Emporiuom of Paint and we shall use our MAGIC COLOR MAKING machine to provide paint of the exact same shade"
Before you could say "legs on a donkey", I was there, clutching my purple mug.
"Excuse my, dear sir, could you please make paint to match my mug?" I cried piteously.
"Sure Missus! Give it here and my MAGIC COLOR MAKING machine will tell me what tints to use!"
The mug was scanned and I waited nervously. When he was done I had a pot of paint, exactly the same shade of purple.
"Oh wise paint wizard!" Said I, " what shade of purple would you call this paint"
"Nah Missus, it's nae purple, it's blue. See ya got ya C4 and ya K7 and a touch of B9. That's blue that is"
I was a broken women. Saddened and ashsmed I made my way home.
Where I smashed the stupid blue mugs and put them in the bin. And never mentioned them again.



True story

[Hermit]

to reiterate:-
If you define colour as an attribute of wavelength, then purple, without a shadow of a doubt, does not exist.
If you define it as the experience felt when neighbouring red and blue cone cells are stimulated but the neighbouring green cone cell is not stimulated then purple certainly exists.

Reiterate? Please quote the relevant passage saying that in any of your previous posts.

I agree that if you define colour as an attribute of wavelength, then purple, without a shadow of a doubt, does not exist, or to put it in other words, there is no such spectral colour. There is, however, a real colour called purple. It exists manifestly enough - unless one dogmatically asserts that only colours displayed in a rainbow really exist.

I withdraw the description of you being confused. Dogmatic / narrowminded are more appropriate adjectives for your assertion.

[Blind groper]

Just a small spectral digression.
When I went to high school science class, I was taught there were 7 colours in the rainbow, which we dutifully learned as red, orange, yellow, green, blue, indigo, violet. Mnemonic Roy G Biv, or alternatively Richard Of York Gave Battle In Vain.

Later in life I discovered something that is totally obvious if you only look at a rainbow. There are, in fact, only 6 colours. There is no indigo.

It appears that the first person to write about spectrums was Isaac Newton, and he was a man of his time. That is, as superstitious as all get out. At the time, there was a belief that seven was God's special number. Based on that, the spectrum had to have 7 colours. Didn't it?

Newton stared at the spectrum looking for the 7th colour, till he perceived something, which he called indigo. But it was never there. The rainbow has only 6 colours.

If you do not believe me, check it yourself. Next time you see a rainbow, count the colours.

[PsychoSerenity]

Just a small spectral digression.
When I went to high school science class, I was taught there were 7 colours in the rainbow, which we dutifully learned as red, orange, yellow, green, blue, indigo, violet. Mnemonic Roy G Biv, or alternatively Richard Of York Gave Battle In Vain.

Later in life I discovered something that is totally obvious if you only look at a rainbow. There are, in fact, only 6 colours. There is no indigo.

It appears that the first person to write about spectrums was Isaac Newton, and he was a man of his time. That is, as superstitious as all get out. At the time, there was a belief that seven was God's special number. Based on that, the spectrum had to have 7 colours. Didn't it?

Newton stared at the spectrum looking for the 7th colour, till he perceived something, which he called indigo. But it was never there. The rainbow has only 6 colours.

If you do not believe me, check it yourself. Next time you see a rainbow, count the colours.

You can split it into as many colours as you like. I believe there have been studies that show that depending on how many colours you have words for and learn as a child, it has a lasting effect on what colours you can perceive and differentiate as an adult.

[Pappa]

By no commonly accepted definition does colour equal wavelength. The closest thing we have to wavelength is a colour's hue. But a given colour is more than just its hue. The saturation, lightness and brightness of a colour all play their part too. If we used wavelength alone to define colours, then pastel colours, dark forms of colours, ochres and all sorts of other commonly accepted colours couldn't exist.

[pErvinalia]

..and well told, fishie.

No such colour.

Correction: No such spectral colour. Purple does exist as a colour, and it is a real colour despite not appearing in the spectrum of a rainbow. You can see it on robes of priests, monarchs and in paintings. Purple coloured dyes have been around for well over two millennia. To help you resolve your confusion, check this link.

Sorry I gave you the impression of being confused, though where you get my ‘confusion’ from I’m not sure.
Let me assure you that I’m not confused.
(BTW It’s considered rude in my culture to call someone confused for no proper reason. OTH if you were trying to be deliberately insulting, feel free to go fuck yourself)

Hermit strikes again..

[pErvinalia]

I see Wikipedia provides a wavelength for violet (380–450 nm) but not purple.
http://en.wikipedia.org/wiki/Violet_%28color%29
http://en.wikipedia.org/wiki/Purple

What's the difference between violet and purple? I figure they are the same. Violet is maybe a bit more bluish, perhaps? Purple a bit more reddish/pinkish/magenta-ish?

[pErvinalia]

to reiterate:-
If you define colour as an attribute of wavelength, then purple, without a shadow of a doubt, does not exist.
If you define it as the experience felt when neighbouring red and blue cone cells are stimulated but the neighbouring green cone cell is not stimulated then purple certainly exists.

Reiterate? Please quote the relevant passage saying that in any of your previous posts.

I agree that if you define colour as an attribute of wavelength, then purple, without a shadow of a doubt, does not exist, or to put it in other words, there is no such spectral colour. There is, however, a real colour called purple. It exists manifestly enough - unless one dogmatically asserts that only colours displayed in a rainbow really exist.

I withdraw the description of you being confused. Dogmatic / narrowminded are more appropriate adjectives for your assertion.

And "stick up one's arse" is a good description of your "assertions".

[JacksSmirkingRevenge]

I see Wikipedia provides a wavelength for violet (380–450 nm) but not purple.
http://en.wikipedia.org/wiki/Violet_%28color%29
http://en.wikipedia.org/wiki/Purple

What's the difference between violet and purple? I figure they are the same. Violet is maybe a bit more bluish, perhaps? Purple a bit more reddish/pinkish/magenta-ish?

Violet is purple. It actually lies to the redder end of what we would call purple (although to my eyes, yes, it does look like it's got more blue in it than red. Dunno why this shoul be.)
Meh, colour names are somewhat arbitrary, anyway. - At what point does a colour become another colour?

[Xamonas Chegwé]

I see Wikipedia provides a wavelength for violet (380–450 nm) but not purple.
http://en.wikipedia.org/wiki/Violet_%28color%29
http://en.wikipedia.org/wiki/Purple

What's the difference between violet and purple? I figure they are the same. Violet is maybe a bit more bluish, perhaps? Purple a bit more reddish/pinkish/magenta-ish?

Violet is purple. It actually lies to the redder end of what we would call purple (although to my eyes, yes, it does look like it's got more blue in it than red. Dunno why this shoul be.)
Meh, colour names are somewhat arbitrary, anyway. - At what point does a colour become another colour?

About 3 miles due north of Congleton.

[mistermack]

The colour white has no wavelength.
The colour black has no wavelength
The colour grey has no wavelength.

But the non-colour infra-red DOES have a wavelength.

[JacksSmirkingRevenge]

White is comprised of all the colours. It's a mixture. - If you take a colour wheel and spin it fast enough it appears to turn white.

[PsychoSerenity]

By no commonly accepted definition does colour equal wavelength. The closest thing we have to wavelength is a colour's hue. But a given colour is more than just its hue. The saturation, lightness and brightness of a colour all play their part too. If we used wavelength alone to define colours, then pastel colours, dark forms of colours, ochres and all sorts of other commonly accepted colours couldn't exist.

Also, I think pretty much every naturally occurring material or system, essentially everything other than specific technology designed to avoid it, emits or scatters light in combinations of many different wavelengths. You'd never normally see individual wavelengths. Even a rainbow does not give an entirely accurate match of the spectrum.

[Svartalf]

I see Wikipedia provides a wavelength for violet (380–450 nm) but not purple.
http://en.wikipedia.org/wiki/Violet_%28color%29
http://en.wikipedia.org/wiki/Purple

What's the difference between violet and purple? I figure they are the same. Violet is maybe a bit more bluish, perhaps? Purple a bit more reddish/pinkish/magenta-ish?

none, violet and purple are two words from different linguistic roots designating the same group of shades.