Terry Miura • Studio Notes


Sunday, January 11, 2015

A Little More on the Color Wheel



It seems there's a bit of confusion on the color wheel thing in the previous post. I had a couple of questions asking me about the relationship between chroma and value. I said that in the color wheel I presented, in each slice of the pie, the chroma changes (becomes grayer) but the value remains the same as we travel toward the center.

Sometimes our eyes are tricked into seeing lower chroma as lower (or higher) value, when they're actually the same. I really can't tell you what the scientific reason behind that is. I have noticed a tendency to confuse lighter (value) with brighter (chroma). But confusing the terminology is one thing, to actually perceive a color as lighter or darker than it is something we all experience to one degree or another. 

Squinting is always a good way to simplify what you're seeing - by limiting the amount of light that the eye receives, you limit the amount of information as well, and we see only the simplified picture. If you were to squint at my color wheel, I think you can see that the values do not change within any slice of the pie.

…that is, within reason. I don't claim my pie is perfect, but the aberrations are (should be) within a few percentage points at most.

Below is a good illustration - I converted the color wheel to grayscale in Photoshop to eliminate hue information. All we see now is value.  See what I mean?



I did the same with a couple of color wheels that I found online. Here's one in which the colors move toward black as it moves toward the center.



And another one in which the color moves toward white as it moves toward the center. It's got a hole in the middle, but you can see what I mean. 




In all three examples, all I did was convert the color file to grayscale. There's a huge difference in what information is presented, isn't there?  I really don't find the second and third color wheels helpful. I mean the second one shows what happens to a pure hue if you mix it with black, and the third one shows what happens when you mix it with white. That's not really useful information for a painter. I don't want to know what happens to red if I mix it with black or white. What I want is to be able to show how chroma affects color. I want to show that value and chroma are two different functions.
That changing the chroma of a color doesn't change its value. (Changing the value of a color does affect its chroma. Chew on that one! hint-the second and the third color wheel does show us this fact)


Anyway, I hope these examples clear up the confusion about chroma and value. Remember to squint!


9 comments:

  1. What I can see in fact is the contrary, that every color has its own value, ones reflect more light than others, maybe because of the wavelength of each one, I don't know. Oh! I have just realiced, I thintk I also am mixing up brigther (the proper of each color) with value (the amount of light that it gets?).

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  2. Thanks for your comment~ I'm not sure what you mean, but yes each color has its own value. That's not contrary to my point that in my color wheel, the value of a color doesn't need to change at all as it loses or gains saturation. I hope that makes sense~

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    1. If a color loses saturation by adding white or black, I understand you are changing its natural value (or its natural bright, now I don't know how to call it) and even, when talking about color-pigment, by graying down the color you are moving it towards another one (for example yellow moves to green when adding black).

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  3. Also it is true that computers doesn't use sustractive synthesis (color-pigment) but additive (color-light).

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  4. It was very useful for me. Keep sharing such ideas in the future as well. This was actually what I was looking for, and I am glad to came here! Thanks for sharing the such information with us.

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  5. It is very helpful information. I have an another question about shade and saturation.
    I have learned that shade means color adding black. Is that true the shade color has low saturation? Thank you very much.

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    1. The term "shade" has a couple of definitions. "Adding black to a color" is the definition used mostly in paint manufacturing context, to show what happens to a color when mixed with black - (mixing with white is called "tint"). For us representational artists, it's not really helpful or relevant because rarely do we formulaically mix black into a hue to achieve a color. (OK, I'm speaking for myself and not for everyone, but as far as my little world of representational painting goes, I think most will agree with me) I think in the context of practicing representational painting, "shade" is used more generally, to point to any kind of variation of a hue. To a painter, "a shade of green" doesn't mean it's mixed with black- it just means a variation of a green. To a paint manufacturer, it specifically means the green is mixed with black. So two different meanings.

      Having said that, to answer your question, mixing any hue with black will reduce its saturation as well as its value.

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    2. Terry, thank you very much for your answer. Right now I understand. ^_^

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