You are close to the mark and probably understand it better than you expressed it in your brief statement.

White balance is achieved by getting a neutral mix of red, green and blue for something that we know is supposed to be white even if the light incident on the subject is not properly balanced. For example, the white paint in Bob's first image appears to have been made white regardless of the color of the incident light, including any light reflected onto the white paint from other walls, the ceiling and floor.

In color photography there are three primary colors (red, green and blue) and three complementary colors (cyan, magenta and yellow). The complementary colors are respectively the exact opposite of the three primary colors.

Anyone who has used a WB probe in a color editor should be aware that white balance uses two trade-offs - yellow vs blue (temperature) and green vs magenta (tint). We only need two because the third (red vs cyan) is controlled by the other two trade-offs. In other words, there are only two degrees of freedom in white balance, not three.

Things start getting difficult when a scene in not overwhelmingly bathed in light of the same color like we can manage in the studio.

Out of doors in broad daylight there may be one white balance for direct sunlight and a different color of light coming from the blue sky (about 3 or more stops less intense). This can result in blueish shadows but that might look normal. We might be more bothered by the green tint that we get from sunlight being filtered through a canopy of leaves.

It's easy to deal with all of this simply by leaving the camera's WB set to Daylight. WB does not alter the raw file. It's easy to correct everything during the raw conversion on your computer.

This article contains some advanced considerations for capturing and portraying color scenes, subjects, etc. As such, it may be of interest to a select few. Additionally, if you are converting to black and white, having accurate colors in the initial photograph is essential to rendering the appropriate shades of gray in the conversion. If you aren’t one to desire doing a bit of additional processing, it’s best to skip this.

What is Color Cast (Hue Contamination)?
Whether you’re aware of the correct terminology or not, you have likely experienced hue contamination happening in your photographs already. Put simply, hue contamination is when one color is affected by the presence of another color in close proximity or filtered through a colored environment. A color cast is an overall wash of color caused by the light in which a photo was shot.

Hue contamination is a, sometimes, subtle but, noticeable color tint to an image. This is seen as an overall cast. Casts occur when white balance is inaccurate or light is contaminated with a color. This article is focused on the latter. An example is light bouncing from a colored surface or filtered through a colored environment. Though not really a topic for this article, if the color cast is due to white balance inaccuracy, it's an easy fix in post-processing software with white balance/tint sliders. If the cast came from light reflected off a colored surface or filtered through a colored environment, it can require a more in-depth fix involving selective color adjustments.

For example, if you’re photographing two subjects side by side, one of them is white and the other one red, the white subject will likely take on a pinkish tone due to the fact that it’s receiving bounced light from the red subject close by.

This hue contamination happens around us all day every day and we are so accustomed to it that most of us never even notice it. So why bring it up? I bring it up because it’s contamination when it happens in our shots. It's especially disconcerting when we aren’t aware of it.

We may even ignore it and not even try to correct it. Regardless, hue contamination is there and we should take note and address it. What if we are truly concerned about portraying the colors as we visually observed them.

Let's consider doing a color photograph in the woods. The surroundings are green, the leaves in the trees, some bushes and maybe there’s even green grass on the floor around you. The daylight comes through the trees, is reflected off all the foliage, etc. The entire scene is enveloped by this green influence. The tree bark, usually a brown color is affected by this environment of green. Not quite what your eyes revealed but definitely caught by the camera.

What About Just Using White Balance?

White balance is based on the Kelvin scale that specifically deals with balancing a certain range of colors based on temperature. So no matter how hard you try, a lot of these hue contamination shots simply can’t be fixed with white balance alone. Black and white photographers have a slight advantage here but for a more accurate conversion, hue contamination needs to be considered prior to that conversion. Remember, the hot-or-cold Kelvin temperature scale starts at absolute freezing 0K (-273.15ºC) while the hue-based Kelvin scale relating to color temperature starts with black as the zero point.

Hue contamination is often a localized effect. Let’s revisit that white subject that looks a little pink now because it was next to a red one. Applying color balance to correct the white subject without affecting the whole image is near impossible. This makes hue contamination such a troublesome problem and one that is oftentimes overlooked.

We have mentioned hue contamination. So what is hue?

Hues are made up of the three primary colors (red, blue, and yellow) and the three secondary colors (orange, green, and violet) that appear in the color wheel or color circle. When you refer to hue, you are referring to its pure color. That is the visible spectrum of basic colors that can be seen in a rainbow. When hues are combined with other color qualities, such as saturation, chroma, or intensity, then the resulting combination is known as the color’s chromaticity.

Is There a Science Behind Hue?

Each pure hue correlates to a different dominant wavelength of light that is then received and processed by the human eye. In other words, different hues correspond with a different wavelength of white light that the human eye/brain interprets as pure color.

What Is the Difference Between Hue and Color?

It’s easy to confuse the word hue with the word color, and they are often (incorrectly) used interchangeably. Color is the broad term that describes every tint, tone, hue, or shade that the human eye can see, including white, black, and gray.

The definition of hue, on the other hand, refers only to the pure spectrum color names found on the color wheel: red, orange, yellow, blue, green, and violet.

Overall, every color has a dominant hue. For instance, the color “navy” has a blue hue, and according to color theory, “magenta” has a dominant hue of violet.

In digital photography, colored light can also be measured as color temperature. Every light source has its own hue. Colors from light sources that move towards blue are considered “cooler” temperature-wise, whereas colors closer to red are considered “warmer.”

What Are Tints, Tones, and Shades?

Color is not constant, and hues can be mixed, manipulated, and changed to create colors that appear lighter or darker:

Tints are created by adding white to any hue found on the color wheel, which desaturates and lightens the hue. You can also combine hues together and add white to create a tint of that specific color blend. When you see colors that appear as pale hues, the effect has likely been obtained through tinting.

Tones are created by adding grey (or a mixture of black and white) to a hue. Depending on the amount of grey added, the tone may be darker or lighter than the hue it was added to. Shades are created by adding black to a hue. The amount of black added will affect the darkness of the shade, and will often make the original color appear “dark-hued.” You can use different shades of a color to achieve gradation, which refers to the technique of gradually transitioning from one hue or shade of a color to another.

What is Radiosity?
Radiosity was taught years ago in the film days. Currently, It's hardly mentioned in association with photography anymore. If it is used currently it is more related to how light and color act upon one another in computer-generated worlds. It has made quite a bit of advancement in 3D modeling. It's how light affects one surface when in proximity to another. This gives those making 3D models textures and added depths of realism to the models they create.

However, we photographers find it the bane of creating realistically rendered photographs, especially in portrait work. I suggest, for those not faint of heart, look up Radiosity in Computer Graphics page on Wikipedia. ( https://en.wikipedia.org/wiki/Radiosity_(computer_graphics) ). I’ll warn you now. There’s math involved.

Regardless of what you want to call it, or if you want to ignore it, hue contamination is a very real problem for us photographers, That is if we want to depict objects like people, cars, clothing, and so on in the best possible way.

No client, or maybe even yourself, wants to photograph a white subject and produce a photograph that has a slight pinkish cast to it.

Color ( Hue) Contamination in Action

In the attached photographs, used with the gracious permission of those who took them, I've included the original and next to it a “gross” hue correction, to illustrate the points of this article. I've also included the selection of the predominant hue of the scene.

Taking a Closer Look

At first, you may not think it’s a big deal. Our eyes and brain are so accustomed to normalizing color variance when it’s in proximity to similar tones, but as the images are adjusted you should be able to see just how dramatic the effect is. Almost every scene is affected by a blueish hue, due to the sky. Landscapes can be affected by dirt/sand (brown), foliage (green), etc.

How Can This Knowledge Be Put to Practice?

You may look at the example images and think that it’s just a byproduct of taking photos. There’s no use worrying about it. Although there are times when this can’t be avoided, hue contamination is very real and it is something we can adjust, now that we know it's there.

As shown in the attached images, hue contamination is always there in color photographs. However, we can reduce the effect through judicious adjustment.

Can I Use This Knowledge to My Advantage?

The good news is that you can use this hue contamination effect to your advantage if you’re clever. Remember that this radiosity isn’t exclusive to color — you can use blacks and grays to add dimension to your subjects. Being aware of it allows us to adjust for it in processing. It may be that in certain situations the colors are outside the white balance spectrum and this presents more work to do in processing.

So, in conclusion, you are now aware of hue contamination. How you wish to deal with it is up to each of us.

For most of us most of the time, KIS, keep it simple, is what we do. We adjust white balance, WB, with a white card, some with a gray card, doing it quickly and assume that for the next hour our setting will be close OR we allow the auto to set the WB. Auto which is what I do most of the time. For my IR camera, I use "custom WB" and a card.

In edit, we can tweak color. Keeping things simple we enjoy photography more... when less of a chore. Since we can adjust a lot of photo color and exposure the thing that we must give attention to is composition and taking multi shots. I have memories of an old fishing boat in a canal... I took one shot... it was in Argentina quite away from my home there never to go again.

Composition too is a technical psycholical/culture-based subject. The art and psychology department coupled in this lengthy work which is free. "A psychological exploration into how people create, share, and react to images
in the age of cyberspace and digital photography. Title... Photographic Psychology: Image and Psyche" -
Richard Zakia, Professor Emeritus, Fine Art Photography Department, Rochester Institute of Technology"
http://truecenterpublishing.com/photopsy/article_index.htm

Rochester... there was a great company there, Kodak, who had the first working digital camera and fools in management declared "We Make Film" oops. Just like GM laughing at those little imports... oops!! Or collecting and shredding their Chevrolet E-cars saying it was a foolish venture and bowing to the petro industry ... oops!

For most of us most of the time, KIS, keep it simple, is what we do. We adjust white balance, WB, with a white card, some with a gray card, doing it quickly and assume that for the next hour our setting will be close OR we allow the auto to set the WB. Auto which is what I do most of the time. For my IR camera, I use "custom WB" and a card.

In edit, we can tweak color. Keeping things simple we enjoy photography more... when less of a chore. Since we can adjust a lot of photo color and exposure the thing that we must give attention to is composition and taking multi shots. I have memories of an old fishing boat in a canal... I took one shot... it was in Argentina quite away from my home there never to go again.

Composition too is a technical psycholical/culture-based subject. The art and psychology department coupled in this lengthy work which is free. "A psychological exploration into how people create, share, and react to images
in the age of cyberspace and digital photography. Title... Photographic Psychology: Image and Psyche" -
Richard Zakia, Professor Emeritus, Fine Art Photography Department, Rochester Institute of Technology"
http://truecenterpublishing.com/photopsy/article_index.htm

Rochester... there was a great company there, Kodak, who had the first working digital camera and fools in management declared "We Make Film" oops. Just like GM laughing at those little imports... oops!! Or collecting and shredding their Chevrolet E-cars saying it was a foolish venture and bowing to the petro industry ... oops!