I can see minute internal molecules/particles in air with my NAKED EYES. what I do?

[James R]

exchemist:

As I understand this graph, the 3 types of cone will all be activated to varying degrees by a particular wavelength and the single shade of colour we perceive is the result of how the brain merges the 3 signals.

Yes. The red and green cones have quite a large degree of overlap in their frequency sensitivities, which is one reason why red-green colour blindness is the most common kind. The blue cones peak a bit further away frequency-wise (or wavelength-wise).

This also explains (if I recall it correctly) how it is that we can "mix" red and green lights and see the result as yellow, even though there is no actual frequency corresponding to yellow light present at all!

Yellow light does have an actual frequency, somewhere between green and red light. But, as you said, our perception of every frequency depends on how strongly each type of colour cone responds to the incoming light. That means we can, for example, create a perception of yellow by mixing appropriate amounts of green and red light, for instance, rather than using actual yellow light.

In fact, this is why computer displays (LEDs, even old-fashioned phosphor screens) only need three colours for each pixel (RGB). By varying the intensities of the three channels, we can produce a sensory experience indistinguishable (to us) from using a frequency of light somewhere between the peak values of the RGB emitters. It's interesting to think about how a creature with more sophisticated colour vision would perceive our RGB screens. They would not think that they reproduce all colours accurately, for instance.

 

[DaveC426913]

That means we can, for example, create a perception of yellow by mixing appropriate amounts of green and red light, for instance, rather than using actual yellow light.

I wonder if it is possible to distinguish between a red-green yellow and spectral yellow.

I'll bet it's pathological. The demonstrator might set it up so that it's imperceptible to him, only to have the first demonstratee come along and say they look different.

It's interesting to think about how a creature with more sophisticated colour vision would perceive our RGB screens.

And those creatures can even be human.

Tetrachromats can perceive a much finer distinction in the blue-green range than the rest of us.
One tetrachromat (they're mostly women) would constantly find herself amazed at how badly some people mismatch colours in clothing - seeing a green clashing with a blue-green where the rest of us can see no difference.