Color Theory Constant Hue Plates

Art 2600 / Greg Clayton

Munsell constant hue plates assignment

Complete two constant hue plates.

You will be assigned two complementary hues.
For each hue, mix representative examples of the full range of chroma and value offered by each hue.
Arrange your color samples by value (rows) and by chroma (columns), according to the Munsell color model.

This is likely the most demanding mixing/perception exercise in the course. For the first time, you are responsible for accurate discernment and control of hue, of value and of chroma. In prior exercises you were responsible for only one or two of these traits.
You will create two panels from Munsell's 3D Color Model — two constant hue charts. They are called "constant hue" because every color sample on the chart is to have the same precise hue — though the chart inlcudes a pure neutral value staff.

There are two basic strategies for mixing your color samples. Either rely on neutral-mixes to lower chroma, or complement-mixes to lower chromas. Your prior Complement Mix Plate gave you experience with the latter strategy.


        1. Refine your ability to create controlled color mixes — especially your ability to control chroma.
        2. Refine you ability to discriminate color traits — particularly fine hue and chroma distinctions.
        3. Become more familiar with the hue-shift problems and corrections.

Selecting your pair of hues

You will be assigned two hues to work with. They will be complementaries of each other.
(see assigned Hue pairs)

Hue Pair    
1 — Red (5R)
——Blue-Green (5BG)
2 — RedOrange (10R)
—— BlueBlueGreen (10BG)
3 — Orange (5YR)
—— Blue (5B)
4 — YellowOrange (10O)
—— BlueBlueViolet (10B)
5 —  Yellow (5Y)
—— Blue-Violet (5BP)
6 — GreenYellowGreen (10YG)
—— VioletBlueViolet (10BP)
7 — Yellow Green (5YG)
—— Violet (5P)
8 — GreenYellowGreen (10YG)
—— VioletRedViolet (10V)
9 — Green (5G) ——
Red-Violet (5RP)
10 — GreenBlueGreen (10G) ——
RedRedViolet (10RP)


Finished plates

Student Examples

These are examples created by students.
Note that a neutral value staff is included in the chart (on the left).
The intrinsic value row should be as wide as the 8.5x11 page allows (6 or 7 colors).
Every color on the same row should be the same value.
Every color in the same column should be the same chroma.
All colors should have the same hue (other than the neutral value staff). That is, avoid hue shift. (Note the hue shift problems in the red chart on the right.)

In this scan, the bottom row is really too dark for chroma to be apparent — all the colors appear black. It is not uncommon for violet to actually have longer rows at value 3 & 4, once white has been added to Dioxizine Purple.


Note that the upper tints (value 7 & 8) are too dark.



Here hue shift problems are fairly obvious. The tints and the low-chroma tones are clearly shifting to red-violet and even violet. This is due to the black paint used to lower the chroma of the red. Correct this by adding yellow or yellow-orange.

This is a pair of constant hue studies combined on a single chart. Though the alignment of vertical columns is sacrificed, the general progression of chroma from low to high is still evident.


This is a digital complement-pair hue chart — two constant hue charts are arranged on a single board.
You may combine your two Constant Hue Charts this way if you like.



Digital Constant Hue Charts

New: This site allows you to generate Munsel charts that might be helpful for comparison while completing this assignment.
(note that value-order is reversed (white at bottom; black at top) and that the true Munsell 0-10 value scale is used, rather than our simplified 1-9 scale)

These examples are digitally generated slices of the Munsell color model. These will give you some idea of what 20 major hues offer via the Munsell color specification system. Note that under each color swatch is the Munsell specification for that color. (Hue-Value-Chroma)

The exact number of color samples on a given row varies depending on the specific hue and the particular pigment used, as well as other mixing details. So don't try to match the number of colors on each row. Also, unless your computer monitor is color calibrated, the colors on-screen are only approximately correct.

To see a a large view of each plate: Mac — control-click; "View Image" Win — right-click; ?

R5 (Red) R10 (Red Orange) YR5 (Orange) YR10 (Yellow Orange) Y5 (Yellow)
Y10 (YYG) GY5 (Yellow Green) YG10 (GYG) G5 (Green) G10 (Blue Green)
BG5 (Blue Green) BG10 (BBG) B50 (Blue) B10 (BBV) PB5 (Blue Purple)
PB10 (VBV) P5 (Purple) P10 (VRV) RP5 (Red Purple) RP10 (RRP)

Starting your mixes — the intrinsic value row

Begin with the cool hue — it is usually easier to manage than the warm hue. (the warm hue often has some hue-shift issues to resolve.)

The first step is to identify the value of your color. Compare your color to your value staff. Basically, what value is your color strait-out-of-the-tube?

In this next stage you will complete a full row of samples, from neutral to full chroma for your intrinsic value row. Recall that your goal is to mix 6 colors that vary from almost neutral (low chroma) to high chroma in even steps. Maintain a constant value — each color sample should be the same value as your out-of-the-tube color. Maintain your hue — don't let the hue shift warm or cool.

Tactics for Reducing and Controllng Chroma

This is the first color exercise in which you are working to discern and to control chroma precisely.
There are three basic ways to reduce chroma —
a) mix with a neutral (either black & white mixed, or, better, a complement-mixed neutral),
b) mix with a complementary color (recall your tactics from your Complement-Mixed Neutrals plate.)
c) mix with a lower-chroma version of your color (often a brown or other earth color). You will have such lower chroma colors for only a few of your hues.

In practice you'll likely combine these techniques as needed. The key mixing problem effecting your choice is hue-shift.
Note that each of these strategies is explained, or anticipated, by the straight-line mixing method.

Mixing Strategy

The strategy that I suggest makes it easier to control chroma than most strategies. You'll need three "source colors" — colors available for mixing on your palette. You'll need:

a) your main hue
This is the color that your entire Constant Hue Chart represents — usually this is your "straight out of the tube" color.

b) your "neutralizing color".
This is the color that you'll use to lower the chroma of your main color. (usually, a gray, or a complement)

c) a middle-chroma mix.
This is nothing more than a mix of a & b, above.
Why bother with a mid-chroma mix?
To make mixing the other colors easier. Recall that one aspect of the straight-line mixing method is that you should mix with source colors that are as close to your target color as possible. Well, the mid-chroma mix is that "closer color."


Find or Prepare a "Neutralizing" Color

Prepare the paint mixture that you will add to your pure, intense, main color in order to lower its chroma.

Do one of the following:

a) Mix a neutral gray at the same value as the row you're mixing.

b) Mix a complementary color at the same value as the row you're mixing.
(in practice, you may need to add white, black or sometimes a brown so as to adjust your complementary to best match the value of your color.)
You will likely also need to adjust the hue of your complementary hue. That is, most of our "complements" are only approximate and most of our tube-paints are not precise complements to other tube-colors.
Recall your Complement Mix Plate tactics. If you are creating a green constant hue chart and are using a complementary red, you may well have to add some red-violet or violet to your red in order to get a really good mixing complementary.

c) Mix a complement-mixed neutral at the value of your current row. (usually the best solution)
Why is this the "best" solution?
One of the challenges in this assignment is controlling hue-shift. A successful complement-mixed neutral should pose very little hue-shift trouble.

How do I mix it?
Recall your Complement Mix plate — you likely just completed it. Recall how you mixed your "best 3-color neutral" — use that strategy again.

Mix your "mid-chroma" color.

Use combinations of your pure, main color, your neutralizing color, and your mid-chroma color to mix each sample along your row.
Watch for values that shift lighter or darker. Adjust as needed.
Watch for hue-shift and adjust your mix as needed.
Create consistent steps of chroma change. This will be difficult at first, but once you have created your first and longest intrinsic value row, the other rows are easier because you can compare back with your first row — using it as a reference.

Each of the other rows is more or less a repeat of the first row — except that the the rows get shorter and shorter due the decreasing potential of chroma at other values.


Online Paint-Mixing Tool
This Golden Colors resource does a surprisingly good job of emulating the methods and effects of paint mixing. Try it out.
Though the onscreen samples are small, you may be able to try out the effect of mixing the colors you own... though, unless you own Golden brand paints, you can expect some variance.
You can enlarge the browser's image scale... often with Cmd-+ or Ctrl-+. (or check your View menu for a Zoom tool)


Mixing High-Intrinsic Value variations.: Yellow, Yellow-Orange, Orange

(and, to a lessor extent Yellow-Green)

Low chroma, low value yellows can be challenging because of the hue-shift that often occurs as you mix either gray or a blue-violet to reduce chroma.
Here's some good advice for mixing lower chroma yellow-based colors, and, especially low-chroma, low-value yellows (i.e. browns)

Your yellow-browns (burnt umber, raw sienna***) can be used for mixes between high chroma, and low chroma.

Between low chroma and neutral you'll need to either...

...add gray (possibly correcting for hue-shift with red or a red-brown (burnt sienna or red oxide))
...add a complementary blue-violet.




Adding rows

Progress from one completed row to the next row — either up or down.
Your first task is to figure out what the most intense, highest chroma color is on the new row.

To do this, you begin with the highest chroma color on a neighboring row, and then add a small amount of white (if you are raising the value) or a small amount of black (if you are lowing the chroma).
How much white/black do you add? ONLY enough to create a color whose value is right for that row.

Once you have the highest chroma color for that row you will
a) figure out what column it goes in by comparing it with your previous rows,
b) mix a neutralizing color for that row, and then
c) proceed as you did for your first row, completing each sample for your current value.

Once a row is complete, you've got to figure out a) what the highest-chroma color is on the next row and b) what chroma that color is. You don't know either of these until you mix and compare to your completed row(s).

In this example, the intrinsic value of this red is 4. To find the highest chroma at value 5, you add just enough white to create a red that matches value 5. Then compare your new color with the value 4 colors — see which one best matches in chroma.

In this example, the intrinsic value of this red is 4. To find the highest chroma at value 3, you add just enough black to create a red that matches value 3. Then compare your new color with the value 4 colors — see which one best matches in chroma.

After you find your highest-chroma colors, and have compared and placed their chroma, you can go on, as before, to mix the rest of the middle and low chroma samples.




Hue Shift problems


We've talked about how some mixing tactics don't get the expected results. The mixes for this plate will give you even more practical experience with these two counter-intuitive mixing problems:

Hue Shift

The problem: The color changes hue when you don't expect it.

Very often yellow-ish colors will become noticably green, and red colors will shift violet. That is, the common hue-shift instigator is blue — especially blue-biased black pigments.

How to correct it?
Recall your straight-line mixing method — it offers you a strategy to figure out how to correct a shifting color. Basically you identify the problem "direction" -- which way is the color leaning on the color wheel. Then you "pull it back" by adding a complement or near-complement. To correct blue hue shift, orange, yellow-orange or even yellow works well. But note that low chroma yellow-oranges can work quite well — your raw sienna, raw umber or even yellow ochre offer much more controlable corrections than ahigh-chroma cadmium orange.

Value Shift

The problem: The mixed color gets darker than either source color!
But both of my colors are a value-5....
...why is my mix a value 3?!!!

The short answer is, "subtractive color mixing." If you recall how pigments behave when mixed, you'll remember that each color "subtracts" some wavelengths of light from those reflected from you paint — every color you add to a mix of paint darkens the mix.

How to correct it?
— Add white.
— Or add a lighter version of your source colors. Or simply use lighter source colors than your target color.


Alternatives and Suggestions

Find, create and propose some orderly and evokative way to demonstrate the full range of color offered by a single hue, without using squares and a grid!


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