Please add citations for these studies.

If you don't get an answer here, you can also try /r/askhistorians, /r/historyofscience, /r/historyofideas or perhaps /r/philosophyofscience

In general, being told something should have no impact on our vision except in specific, ambiguous circumstances. We want our interperetations of the world to be stable.

One example could be the dress illusion. For some people, being told of an alternate interpretation of the scene causes the dress to appear to be a different color.

Another example might be Fuller et al. 2006. Here, an attentional cue affects the perceived saturation (but not hue) of a stimulus. This is sort of like being told something ("look over here") and having that affect your perception.

Internal states like you describe, no. But contextual information can. For example, in this image all of the eyes are gray. The light that reaches your eye is the same from each eye in the image. But we experience the left eyes as colored.

Here is a video of a color adaptation / afterimage effect. After adapting to the first image, the second, grayscale image appears colored.

Having a word/term (concept) for a color can affect performance in various behavioral tasks (e.g. categorization speed). For example, in Russian there is a distinct word for "light blue". Russian speakers are faster at matching tasks that use that color than speakers of languages that do not have that term. It does not mean that they cannot see the color, of see it inaccurately. Much like if we look at an xray, we see the same image as a radiologist, but they are able to detect patterns and meaningful structures that we cannot. See this article about it: https://www.newscientist.com/article/dn11759-russian-speakers-get-the-blues/

Does the christmas ornament appear any color other than black? If yes, it is reflecting light

Why do you think a sphere cannot reflect light?

Google something like "spherical mirror" or "spherical reflection" or the convex mirror section here: https://en.m.wikipedia.org/wiki/Curved_mirror

What do you mean by "the way the moon does"? What way is that?

Weirdly in what way? There is nothing special about the moon except that it is very large, reflects a lot of light, and is far away (so the reflected light had to travel through our atmosphere).

Part of this is simply about having more information to allow us to make better judgments. If I ask "what's the probability that it is going to rain on Sunday" my answer will be different if I have no other information than if I know we are talking about a particular place and time of year. But then we can represent this as different probabilities: P(rain on Sunday) vs. P(rain on Sunday | we are in Seattle in October and are having a rainy season and it's been overcast and rainy for the last 3 days and is overcast today and the weather app said it was going to rain). And note here that the conditional probability is different from the joint probability! (See conjunction fallacy below.) In the conditional case we are saying that those other events have already happened; in the joint case, we are asking about the probability of it raining AND those other events happening.

This is also related to how we define a probability space. Once we agree on the possible events and outcomes, we can go about assigning or calculating probabilities to them. This is something that we don't always do exactly the same way, especially in ambiguous circumstances. For example, you can interpret my rain question as a question about it raining or not raining on Sunday (those are the possible events that make up our probability space) or as a question about the probability that it will rain on that day of the week vs. other days of the week. We can be primed to think about the problem in either way and this can bias our answers (Criag and Rottenstreich 2003 <- pdf!).

Which bringd up the issue of language / assumptions. When someone asks "what is the probability of rolling a 3" they are leaving out "on one roll of a fair, 6-sided die that has a different number on each side". We generally understand what poaaible outcomes we are considering (the probability space) when we are asking these questions, but sometimes need to be more specific.

Part of what you describe might also be related to the conjunction fallacy which is an example of a kind of probability error people tend to make in judging two events (A and B) to be more likely than just one of those events (A). The classic example is the "Linda problem" from Kahneman and Tversky (1981) that I copy in full from wiki:

> Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.

> Which is more probable?

> Linda is a bank teller.

> Linda is a bank teller and is active in the feminist movement.

> The majority of those asked chose option 2. However, the probability of two events occurring together (that is, in conjunction) is always less than or equal to the probability of either one occurring alone—formally, for two events A and B this inequality could be written as Pr(A and B) <= Pr(A) and Pr(A and B) <= Pr(B).

> For example, even choosing a very low probability of Linda's being a bank teller, say Pr(Linda is a bank teller) = 0.05 and a high probability that she would be a feminist, say Pr(Linda is a feminist) = 0.95, then, assuming these two facts are independent of each other, Pr(Linda is a bank teller and Linda is a feminist) = 0.05 × 0.95 or 0.0475, lower than Pr(Linda is a bank teller).

So I suppose the answer to your question is that it depends on the context and what you are actually interested in estimating. For that we need to be clear and precise and sometimes say more than just one sentence that can be interpreted in many ways.

If you don't get an answer here, you can also try /r/askhistorians, /r/academicpsychology, /r/historyofscience, /r/historyofideas, or perhaps /r/philosophyofscience

If you don't get an answer here, you can also try /r/askhistorians

You can find the basic answer with a simple Google search / on wiki. Please start there and come back with a more specific question.

This is an example of an inverse problem in perception. The light that finally reaches our retina is the product of three things: the nature of the illuminant (what wavelengths are emitted), the surface reflectance properties of an object (what wavelengths are reflected), and the medium through which they travel (what wavelengths are filtered). Here is an illustration (panel A).

So basically there are three physical quantities that the visual system needs to recover from a single value (what actually arrives at your retina). That means that there are lots of possible combinations that can produce the exact same input to the visual system! If more light falls on our retina, how can we tell if it's because the light source got brighter, the object changed color or became more reflective, or if the air became less foggy?

Fortunately, there is a lot of information available in the world that helps us. For example, if there are several objects in a room, then we can see different surface reflectances under the same illumination (holding one of the variables constant). We also can make lots of assumptions based on our prior experiences, such as light usually comes from above etc.

When everything goes well, we achieve what is called luminance and color constancy that is -- we experience objects as having consistent surface reflectance properties despite changes in illumination. This is a very reasonable goal for our visual system: very few objects in the natural world quickly change color, but the illuminantion and medium (e.g. fog or mist) changes all the time every day.

These assumptions of our visual system can lead to fantastic illusions where constancy fails. Classic examples are when you see a sweater in a store under one illumination and then go outside and it's a completely different color. This is in fact the explanation for the dress illusion from a few years back -- depending on your assumption of the color of the light in the store (yellowish or whitish) the dress appears either blue and black or white and gold.

Here are a few other fun examples:

Because we take into consideration that shadows reduce the amount of light reaching our eye, we assume that surfaces in shadow are actually lighter than they appear. Here squares A and B are physically identical (exact same pixel values) but one appears much lighter than it is. Here is a color version and here is a version that shows the effect of the illuminant.

I find this one the most compelling -- the chess pieces are actually identical (not black and white); the only thing that is different is the pattern of the fog (here is the same image with no background/foreground).

Here is an example of the "light-from-above prior". This is actually the same image, just flipped 180 degrees. You can download it and rotate it yourself (or rotate your phone!) and you will see the one that sticks out become the one that is an indent and vice versa. If we assume that light is coming from above, if we have a convex object, the shadow would be below it; if it's concave, then the shadow would be at the top, below the rim/edge where light cannot reach. This is a 2D image so we don't have some of our other 3D cues to tell us about the shape of the surfaces here; however, because the image on the left has a shadow on top, we perceive it as concave/indented, while the image on the right, with the shadow on the bottom, is convex/ a bump. Flipping the image changes the position of the shadpw relative to the object and light source and so we perceive the shape differently. This is actually the same principle for how we would apply makeup to, for example, make our cheekbones stand out: you would put something light above the cheekbone and something dark below; this simulates the shadow that a pronounced cheekbone would cause and makes it appear more like a bump.

So what is the "true color" of an object? Color is not a physical property, but a psychological one / a property of the nature of our visual system and how it interacts with light. The physical property of objects that is relevant for this is surface reflectance, which we can describe objectively and independently of the visual system that detects the reflected light. If we had a different visual system, or, as shown above, if we just change the context or our assumptions about the world, objects can appear (i.e. we can experience them) different, but their properties are constant.