Anyway......

Just to add a little complication to it all these cones overlap considerably in their frequency responses. In particular the red ones are able to "see" well into the blue end of the spectrum. This I would guess makes for interesting responses with purple and violet hues on dark or black backgrounds. In artistic terms. A kind of luminescent, glowing effect. Just guessing but I think this is the reason why.

How the brain and nervous system sorts all of this out is nothing short of amazing. Some brains better than others on an intellectual level. Van Gogh's Starry Night painting for instance wouldn't work at all. If our red cones weren't so wonky as they are. He also knew this effect and exploited it to the full.

Interesting bit of a BBC series:




And very weird. How could the tribe members not distinguish between the blue and green squares
Surely they must see they are at least different, even if they use the same word to describe them? Mind-blowing, really.

How can I increase the colour categories language for my child (tentatively being planned)?

sennekuyl wrote:How can I increase the colour categories language for my child (tentatively being planned)?

Teach it the HEX or RGB values?

Rotflol.

We have ~256 names for colours, but even though the experiments focused on the different shades the initial theme was the 11 categories of colours. Which I took to be different to the names of various colours.

But it seems you are correct. I better start learning.

The psychology of visual perception is a fascinating subject, unfortunately, most of the books I used at Uni for same came from the library, as it was part of the course I didn't expect to use in the future.
However it is known that cultures do not always differentiate colours the same and this may what be happening with the Himba. Although we, of the western cultural tradition, name seven colours in a rainbow, not all cultures do the same.

Wiki here: http://en.wikipedia.org/wiki/Colour_vision
mentions that nobody is sure why the Himba name colours differently in that they differentiate more variations in green than Westerners do, the assumption in the article is that it may have something to do with their lifestyle. However it is possible that if they are all very closely genetically related that there then maybe a different colour response at retinal level.

If you want to teach colour values then I suggest the Munsell Colour Solid:

Colour perception (I will not use colour vision in this case) is interesting as it is a lot more complicated, than first assumed.

We all tend to think that colour perception takes place at the level of the retinal cones only, after all they contain the visual pigments which are responsible for the colour response. We must remember though, that there are only three colour visual pigments: red, green and blue. To perceive yellow therefore, the the green response must be stimulated but must also be inhibited by the blue response ie Y=G-B. This part of perception takes place in the retina but in the plexiform/ganglion layer.

Further processing takes place at the level of the lateral geniculate nucleus, roughly halfway between the optic chiasm (just above the pituitary fossa) and the visual cortex where the final processing takes place.

Colour naming, is the psychological part, and is usually covered by the phrase "psycho-visual perception" and this is where, as with most things in this area, we get into deep water.

A person's perception of colour can be affected by several mechanisms ( this is not an exhaustive list) but apart from the lack if the appropriate visual pigment, changes in the ocular media, especially the lens as it becomes cataractous will noticably affect the blue response. Changes in macular pigment has been shown to cause changes during aging.

An interesting point about colour perception is the eye/brain's ability to maintain perceived colour balance. To demonstrate this wear a pair of sunglasses, a dark brown tint will demonstrate best, and go look at, say a florists, most flower colours will appear normal if a little dark or dull. If you then look at the light transmission curve for the tint you will see how the colours should have been altered due to the peak absorption wavelengths. If you then look at the same scene throught the tint , but held at a reasonable distance from the eye, you will see a completely differently coloured scene. This is because the brain has the ability to keep a reasonable colour balance, something a camera cannot do.

Hmm, in Vietnamese the word for blue is just the same word as green with a modifier. I might start looking for this in my kids.

@ramseyoptom

I find the discussion on color so far to be extremely interesting. Not least because I myself have color vision deficiency (I'm told in the red/green spectrum), AND I'm an artist (3d modeller and texture painter. I also paint in oils as a hobby). It took a lot of effort for me to overcome the issue in my own way. Although I have worked to the point where my painting is mostly indistinguishable from a person with "normal" color vision, it's still a challenge for me. I don't want to derail the topic, but I wonder if we can continue this discussion? I would like to better understand color perception.

@OldSkeptic
I've only just gone through this thread, and I'm actually a little sick right now, so I might not fully grasp what you are saying, but wrt to the section where you asked about people seeing cars of a certain color under different lighting and then you highlighting certain texts and asking how people would perceive the colors of the text. Well, in the line where you asked the difference between blue or yellow and then blue or orange, I actually see both sets of text as yellow. The only difference I can see between the two colors is only that the orange set is slightly darker than the yellow text. Possibly because red is darker as a color then yellow, and it affected the orange (but that's just a guess base on my painting experience).

Other colors I have issue with is the green in traffic lights. Most of the time, I see it as white. If the lighting is good, I might actually see that it's some kind of cyan. The green is totally lost on me unless I really squint. But my main challenge is really red. Yellow ochre (by Daler-Rowney) is a paint pigment that is mostly yellow, some reds, and a tiny amount of green. Yellow green (by Rembrant Colors) is yellow and green. To me, both colors look the same (except the yellow ochre looks slightly darker). The red portion of yellow ochre is completely not visible to me. On my color palette, if I didn't seperate the two colors with labels, I would mix the two of them up all the time.

Edit:
In fact, in the diagram that ramseyoptom put up, I see the red-yellow and yellow-green in the same way I see the yellow ochre and yellow green.