Simultaneous contrast is a natural phenomenon of the mind's eye relating to the appearance of color for art.

In effect, simultaneous contrast exaggerates the differences between hue, value, and chroma properties of adjacent colors to the naked eye.

In other words, the appearance of a color can look quite different depending on what colors are beside it. Since color is not normally seen in isolation by the naked eye, this effect is always at work.

Two key factors impact the look of one or both adjacent colors in simultaneous contrast...

(1) differences in color properties (hues, values, and chromas)
(2) differences in area size (e.g large color mass next to small color mass)

The most common "net effect" of these factors is that one of the adjacent color areas will look lighter or darker; richer or duller; redder, yellower, greener, or bluer; and/or warmer or cooler than what it really is.

There is also a case, under some circumstances, where the appearance of both colors change to the point where only a third color can be perceived (see Optical Color Mixing below).

Let's take a look at a couple of examples.

Diagram 1

In Diagram 1, the green circle on the yellow background (A) looks cooler and bluer than what it really is while the green circle on the bluish-green background (B) looks yellower and warmer than what it really is. In reality, the "green" in both circles is identical.

Diagram 2

In Diagram 2, the gray circle on the black background looks lighter than what it really is while the gray circle on the white background looks darker than what it really is. In reality, the "gray" in both circles is identical.

Optical Color Mixing

Optical color mixing is a special case of simultaneous contrast where the area size of both adjacent colors is too small to be identified individually by the naked eye.

In this case, a third color or a gray is created in the mind's eye from the two adjacent colors (see Buster below for optical gray effects from pure complementary colors).

In the technology world, optical color mixing provides a practical way to create color. For example, all the colors from your color printer are created with small dots of 3 primary colors plus black (CMYK - cyan, magenta, yellow, black). Likewise, the colors on your computer monitor are created with small pixels of 3 primary colors (RGB - red, green, blue).

In the art world, we see optical color mixing used creatively. French impressionists, like Camille Pissarro and Monet, created the illusion of more color and vibrant grays with small spots of rich color layed in side by side on the canvas.

So, what does this all mean to the artist?

It means that color perception is relative and not absolute. Therefore, since instances of color are not normally seen in isolation by the naked eye, the viewer is always subject to these effects.

Good or Bad

To artists then, the impact of simultaneous contrast effects can be a good thing or a bad thing.

For amateurs, it is usually a stumbling block because they are not aware of it or they underestimate it's influence or importance. For professionals however, it can be an opportunity for creative expression.

A Stumbling Block

In art, the key thing to keep in mind about simultaneous contrast is that the effect tricks the mind's eye into seeing colors that are not really there and not seeing colors that are really there. It's an optical illusion.

Consequently, the amateur tries to paint what they think they see which often is an exercise in frustration. Some colors come easy but many not; especially dull colors. The symptom often becomes evident when the amateur just can't seem to get certain color effects right even though they don't have vision problems.

Let's take a look at what can happen.

I created a virtual art study with Artworks Basic from a sunset photo to study the distribution pattern of blue tones. Using the "mask by color pattern" method (one of the virtual methods in the software), I easily found that much of what appeared to be blue is not blue at all.

Compare Diagrams 3 and 4.

Diagram 3


Diagram 4 - No Blues

In Diagram 4, the blue tones are masked out. What appears to be blue in many areas of the lower sky are really dull oranges, yellows, greens, and cyans.

In this example, the simultaneous contrast effect from the neighboring rich yellows and oranges next to the much duller shades of the same hue create the appearance of different shades of blue. So if you try to paint what you think you see realistically, it will not look right.

Furthermore, the longer you look at the colors, another closely related phenomenon comes into play called the after image effect (also called successive contrast).

The good news is that misreading color due to simultaneous contrast and the after image effect can be overcome with good tools and good teaching. The key is use the tools as an aid to recognize these effects when you see them and understand what makes the colors look that way. Then you are equipped to achieve the effects you want on canvas with paints (or what ever medium you use).

A Solution

Today, the negative impact of simultaneous contrast effects can easily be overcome using the virtual methods tools in Artworks Basic.

Using virtual methods, you can study the hue, value, and chroma patterns in real time and in depth using visual design principles. They enable you to overcome tricks of the eye while gaining deep color knowledge about your favorite subject. Learning time is reduced considerably.

Once you recognize and know what is going on with any particular effect, you are then equipped to apply this knowledge on the canvas.

An Opportunity

Understanding simultaneous contrast also provides an opportunity for creative expression.

The impressionists were well aware of these effects and were skilled in using it to creative advantage. With just a few colors they could create the effect of much more color and variety than was actually there which included vibrant neutral effects from pure colors (see Buster below).

So, if you are serious about art, you may want to invest time studying the fascinating effects of simultaneous contrast. You'll be richly rewarded.

Sunny Snowscapes, No Yellow

Here is a story about a painter who lived in the Baffin Islands. She painted many scenes of glaciers and snowscapes.

What I found interesting about her paintings was that she did not use yellow on her palette, yet the effect of sunlight was everywhere. She used her knowledge of simultaneous contrast and the after image effect to create the effect of glowing sunlight in the snow and ice.

The more the viewer studies these paintings, the more intense the sunlight becomes. By skillfully placing "blues" and "blue purples" next to more "neutral" tones of the same general hues, she was able to create the effect of sunlight in the snow without actually using yellow paints.  

Buster - Optical Gray from Pure Colors

Buster is an optical gray study. One of the reasons I created Buster and other optical studies was to demonstrate the effects of simultaneous contrast and explain its relevance to art. These charts also prove that the hues in the virtual color system (Gagnon Color System™) in Artworks Basic are gray balanced for art.

Gray balanced means that the hues opposite each other in the color wheel are true optical complements. This is the case for the screen colors in the software and the printed colors on the charts that come with the software.

Try This

Position Buster on your screen so you can see the whole image, then stand back a few feet. You will see eight shades of gray.

However, when you get close to the screen you can see that there is no gray in the image at all (except for my signature). The whole image is composed of eight pairs of greens and magentas at eight value levels (see the numbered pairs from 8 to 1 on the chart).

Here we have the simultaneous contrast of completely opposite hues (complements) at different values and different chroma levels. As an artist, I used my knowledge of simultaneous contrast and carefully chose colors to create the effect of a black and white image with color.

I also did the same thing with printer inks. The printed version of Buster is included as a bonus with the other printed charts when you purchase a license for Artworks Basic.

Download 30 Day Trial

If you want to explore the digital version of Buster using virtual methods, rightclick on the Buster image above, select "Save Picture As...", and save it to your computer.

Next download the 30 day trial version of Artworks Basic and install it.

When ready to go, do the following...

1) open the above image (called "Buster_OpticalGray_SMG2_idx.png")
2) if Canvas Window is ON, click 4th button (main toolbar) to turn it OFF
3) click on the "Study Tools" button (last button) on the main toolbar
4) on the "8 Hues" toolbar, click "G" a few times then click "M" a few times
5) now reset it back to normal, then click "N" (all the neutrals are gone)

There's much to explore. Have fun.

Philip Gagnon
Inventor of virtual methods for composition