Computer Complements - Confirmed

by Roy Zuniga

On my last post titled 'Compliments of your Computer', I noted that the traditional artists' color complements model does not align with color space in our computers. Using the HSL color space broken into 12 colors evenly divided in the numerical values yielded complements that were not the traditional Red-Green, Blue-Orange, Yellow-Violet. I noted the need for a scientific proof that the new proposed 'normalized' 12 step model did in fact result in neutralization of colors. This afternoon, before picking up my brushes, I decided to use a vector drawing program, Adobe Illustrator, and specifically it's ability to blend two colors in intermediate steps, to prove or disprove the thesis. The result confirmed the thesis, as follows.

Adobe Illustrator doesn't have the HSL model which uses numbers up to 255 for hues. Instead it has HSB which uses a 360 model. So I had to divide the 360 into the 11 intermediate steps to get the same chart -- but the results were the same. To go to the next step and find if the middle blend is in fact neurtral, I then used the blend tool with 7 intermediate steps to oppose complements. For example hue 0 was opposed to hue 180, and this was done for all 12 colors, with Saturation and Brightness dialed up to 100% for all. The resulting middle blend color was in all cases 50% brightness and 0% saturation -- in other words a neutral grey.

If I shifted any colors and opposed them with something other than its 180 degree complement, some non-neutral color was obtained in the middle. Thus the theory is confirmed. Red is neutralized by a turquoise color, not green, for example.

In this HSB 12 color breakdown, however, yellow and orange didn't show up as nodes. So using the RBG controls I dialed in the traditional primaries Yellow, Red, Blue and converted to HSB to chose their complements. The result was the following five opposing sets of colors. As expected, the center colors are also neutral grey. These stripes would fit in the above wheel to the right or left of blends shown. This chart shows more clearly what the complements to your favorite primaries are, according to the computer color space.

Please note that the original file was exported for a web color space for posting on this blog, and the colors slightly shifted due to the limited color pallet of 'web colors'. However, I did verify the colors on the original file, and the middle colors are in fact 50% brightness at 0% saturation (making the hue number irrelevant, i.e. all hues are neutral grey at those percentages).

So the thesis stands. How this translated to artists color practice remains TBD. I would encourage artists to experiment. Keep in mind that artists colors are not always at the highest brightness and saturation for any given hue. A useful next step is to map commercial artist colors to color nodes based on this model, and then do manual blends to confirm or repudiate the theory with artist colors. We could start with numbering the chart above and finding commercial equivalents. Of course the challenge will be to compare a physical pigment with a computer model because monitors are calibrated differently, so perceived color will vary. In the mean time, it won't hurt to use this chart as your color complements chart. If you want a PDF version, just send me an email (zuniga.roy@gmail.com), and I'll get you a chart.

One final note: I'm not an expert in this area, but we need a way to objectively 'read' a commercial artists' color and correlating that to a value in the above color space.

Happy Painting!

copyright 2010 roy zuniga

Compliments of Your Computer

by Roy Zuniga

I was on my computer composing a little matrix of colors to aid the distribution on a palette colors in what I call an opposing complements layout, starting with coolest opposing hottest at the top:

I like this palette because it puts colors that neutralize each other in direct opposition. As I found the colors in the computer color picker for my reference card, I realized that the increments between color numbers were sometimes regular (about 11) -- especially in the range of Yellow/Violet and Green/Red -- and sometimes much larger, as in the Turquoise related hues (which lack complements in the historical model). The computer has a color model (Hue, Saturation, Lightness or HSL) built in (one of several). So I took the highest number (255) and divided by 12 = 21.25. This yielded both the traditional colors we're used to, as well as a few others that fall into main steps (Red is both 0 and 255 because color space wraps):

Shuffling these regular step colors into my old opposing complements model, I noticed there were anomalies, i.e. half steps as well as gaps (shown in black):

The traditional model is shifted and lacks some complements (like those for Turqoise-Blue (149) and Green-Turquoise (106)), and has falsely paired some colors with half-step colors (for example, Orange-Yellow (32) and Red-Orange (11)). So I normalized the colors according to full steps and opposed them so the difference in numbers was always 128:

We'll call this the 'Normalized 12-Step Opposing Complements' model that arranges complements according to the computer color space. This yields a very pleasing matrix that also makes sense mathematically.

Could it be that the traditional theory of complimtary colors that survives in our art books is an evolution of observation limited by the pigments available and is not accurate.

This may explain why mixing direct complements in the old model sometimes shifted tinted colors into adjacent color spaces and didn't strictly neutralize. The traditional model is close enough that subtle shifts in low intensity colors were not perceived or ignored. Moreover, since artists pigments rarely have colors that directly align with the steps, we're used to mixing several colors. In practice, the artist's eye overrides the theory, which is always just an aide to getting started. For these reasons, the traditional model has gone unchallenged in artist's circles. I would encourage artists to validate or invalidate this 12-Step Normalized Complements model.

Now, I'm going to stop messing with the computer and start creating art -- Happy Painting!

copyright 2009 roy zuniga