Philosophy- What Do we See?

Thomas wrote:

The original assignment itself is arbitrary.

That defies belief.

Thomas wrote:

The drug messes with the part of the forebrain that processes the input from the optical nerve. Their brain's language center accurately says what that part of the forebrain thinks it perceives.

Then you're wrong.

An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, tilt, color, movement), and cognitive illusions where the eye and brain make unconscious inferences. They can also be known as "mind games".

To make sense of the world it is necessary to organize incoming sensations into information which is meaningful. Gestalt psychologists believe one way this is done is by perceiving individual sensory stimuli as a meaningful whole.[3] Gestalt organization can be used to explain many illusions including the Duck-Rabbit illusion where the image as a whole switches back and forth from being a duck then being a rabbit and why in the figure-ground illusion the figure and ground are reversible.
In this there is no "Drawn" White Triangle. Click caption for an explanation.
Kanizsa triangle

In addition, Gestalt theory can be used to explain the illusory contours in the Kanizsa Triangle. A floating white triangle, which does not exist, is seen. The brain has a need to see familiar simple objects and has a tendency to create a "whole" image from individual elements.[3] Gestalt means "form" or "shape" in German. However, another explanation of the Kanizsa Triangle is based in evolutionary psychology and the fact that in order to survive it was important to see form and edges. The use of perceptual organization to create meaning out of stimuli is the principle behind other well-known illusions including impossible objects. Our brain makes sense of shapes and symbols putting them together like a jigsaw puzzle, formulating that which isn't there to that which is believable.

Perceptual constancies are sources of illusions. Colour constancy and brightness constancy are responsible for the fact that a familiar object will appear the same colour regardless of the amount of or colour of light reflecting from it. An illusion of colour or contrast difference can be created when the luminosity or colour of the area surrounding an unfamiliar object is changed. The contrast of the object will appear darker against a black field that reflects less light compared to a white field even though the object itself did not change in colour. Similarly, the eye will compensate for colour contrast depending on the colour cast of the surrounding area.

In this illusion, the colored regions appear rather different, roughly orange and brown. In fact they are the same colour, and in identical immediate surrounds, but the brain changes its assumption about colour due to the global interpretation of the surrounding image. Also, the white tiles that are shadowed are the same colour as the grey tiles outside the shadow.

I don't know about that, but I'm certainly beginning to get a sense that we are in less-than-complete agreement.

What do we see with our own eyes?
An Example: I could say that the colour I see is Blue. However, it is just a noun for this colour. To someone else the blue I see could be completley different. To them it could be my version of Green. But we can never know as Colour is unexplainable.

would you say that the wave spectrum of light is a sufficient description of what colour is or only a necessary element ?

Could you clarify ?