semantics: purple vs violet

[bhickory]

Ages ago in a media design class I was taught that purple was a shade of blue and violet was the proper name for red+blue, but now despite what I though was strong Google fu, I can find nothing on the subject. Anybody have any pointers to back up that claim, or did this teacher just make it up and leave me facing a month of dishes for losing the bet?

[spidermike]

As I understand it, purple is combination of rd and blue but vilet is actually a colour in itself (it has its own band in the spectrum) so is what I would consider a 'shade of blue' so I would say your teacher had it the wrnog way round.

You need to be careful as to whether you are talking about colour mixing on a screen versus colour mixing with paints - pains is subtractive in that one pigment blocks part of the 'spectrum' of shades in the other and what you end up with is the remaining colour wavelengths. Mixing light (for example on a computer screen) is additive in that mixing RGB to different extents creates the shades.
When creating with pigments, both are (IMO) red+blue of differeing intensities.

[jferrari]

Violet is the name of the girl I brought to the Deep Purple concert! 

[Otto Phocus]

I am so old that I remember when Indigo was a color.   

Violet is an individual "true" color in the spectrum.  It occupies about 380-420nm.  Violet can be described using objective terms purely from a physical standpoint.

Purple is a combination of Red (620–750 nm) and Blue (450–495 nm).  Purple is a perceived color caused entirely by the human eyes and brain working together.  One can not describe purple in objective terms.

So if you wanna impress your friends you can talk about regions of the light spectrum and the fact that RGB displays have a very hard time displaying violet but instead use purple.

But from a practical photography standpoint, there may be little difference between violet and purple.

[Isaac]

Violet can be described using objective terms purely from a physical standpoint.

…color is not something out there in the world, separate from us.

"The agreed-upon technical definition of color," says Fairchild, "is that it's a visual perception."

[Rainer SLP]

https://en.wikipedia.org/?title=Purple

https://en.wikipedia.org/wiki/Violet_%28color%29

[PeterAit]

Violet is my bossy cousin. Purple is the color her face becomes when you disagree with her.

[bhickory]

Thanks. I had of course read Wiki but was hoping there was some obscure technical jargon use rather than the common one to back her up. Like most of high school, seems she was just plain wrong, and I'll be buying some paper plates for this month :-P

[Telecaster]

Purple is a combination of Red (620–750 nm) and Blue (450–495 nm). Purple is a perceived color caused entirely by the human eyes and brain working together. One can not describe purple in objective terms.

Ack! Quora is full of it. In fact most of the Internet, judging by Google search results, is full of it. All color is "perceived color caused entirely by the human eyes and brain working together." The notion that some colors are linked directly to specific wavelength ranges and will always appear the same regardless of context is nonsense.

We interpret a fairly wide range of wavelengths—in most contexts—as "purple/violet," including wavelengths near both ends of our visual spectrum. The Quora dude isn't completely off the mark in this respect. Very complex processing going on. This is why film emulsions and electronic sensors have typically been poor at mimicing our eye/brain creation of these hues. Films & sensors lack our (subconscious) fine-grained contextual predispositions.

-Dave-

[MarkM]

If you look at the cone response curves you'll see that each of the three has a peak at a certain wavelength and then falls off. At the blue end of the spectrum the short wavelength cone most responsive to blue wavelengths falls off quickly. But the long wavelength cone most responsive to red wavelengths flattens out and remains responsive well into the blue end of the spectrum. What this means as that at the shortest visible wavelengths the the long cone is contributing a relatively larger contribution as the short cone falls off. The result is that the blue becomes biased toward red slightly and we see violet. You can created the same effect by mixing blue and red wavelengths and get the various shades of violet and purple. The only thing that really distinguishes violet is that you can create it with monochromatic light, which you can't for other hues of purple and magenta. This leads people to say things like 'violet is a real color, while purple is only in our heads,' but, as Telecaster points out, this is mostly nonsense.

[Otto Phocus]

Ack! Quora is full of it. In fact most of the Internet, judging by Google search results, is full of it. All color is "perceived color caused entirely by the human eyes and brain working together." The notion that some colors are linked directly to specific wavelength ranges and will always appear the same regardless of context is nonsense.

As long as you realize that it was you that introduced the underlined phrase, and not I. Therefore your new argument does not invalidate my previous statement. I made no statement about color appearing the same.  That is a completely different argument. There is a huge difference between color existing and color being perceived.

Specific colors are linked directly to specific wavelengths.  Color will not always be perceived or appear to be the same regardless of context.  No scientist is claiming otherwise.

[MarkM]

Violet is an individual "true" color in the spectrum.  It occupies about 380-420nm.  Violet can be described using objective terms purely from a physical standpoint.

Purple is a combination of Red (620–750 nm) and Blue (450–495 nm).  Purple is a perceived color caused entirely by the human eyes and brain working together.  One can not describe purple in objective terms.

This idea is tossed around a lot, but it's not really true. Purples and magentas can just as easily be described in spectral terms, they just require more than one wavelength of light to do it. There's nothing more or less objective or "true" about a description of light with a full spectrum than the description of light of a single wavelength.

[Isaac]

There is a huge difference between color existing and color being perceived.

What's your preferred definition of color?