Thursday, November 1, 2012

"Can Color Temperature be Quantified"



It is beautiful today in Austin: sunny and 86 F. After several workshop teaching in a row, I came back to my color research I left weeks ago. After reading my notes, my attention has been brought into the issue of "color temperature". We talk and think about color temperature all the time. For instance, painting shadow warmer when we have cool light. However, the color temperature in art seems so relative and confusing, especially when we deal with greys. To my limited knowledge, I have not seen anyone assign a number to a specific color. But I think number is important. Can you imagine the meteorologist in TV only tells you that tomorrow will be cooler than today, but no specifics? I think that the number "86 F" does give us more information, doesn't it?

Since I don't have a quantified system for color temperature, I have to invent the wheel myself. I wrote myself a tech note as the following. (If the terms are too techie to you, please ignore them at this moment, I will share them again with more understandable words in the future after I get all bugs removed).

I want to establish an absolute color temperature scale. Every color should be specified by a value T for its temperature. The range of T is from 0 (the coolest) to 100 (the warmest). In the HSV color system, I assume the value (i.e. grey scale) change does not affect the color temperature. I also assume the color of Red-Orange (30, 100) is the warmest, and its complementary Blue-Cyan (210, 100) is the coolest. The the temperature T of any color (H, S) can be calculated by the following formula:

T = 50 + (S/2) cos (H - Hh), where Hh = 30 is the hue value of the warmest color.

The image above is an example of the calculated temperature of 12 selected colors. I hope they make sense.

7 comments:

Michael King said...

I do believe a quantitative scale will not do much good as temperature is very relative to the surrounding pigment.

Bruce Bingham said...

I think you are on to a very interesting and innovative topic that I have not seen before. The color is all relative to the color next to it as the previous comment states, but I feel it would be useful information to do a color study with. Just like we need to know transparancy, value, and saturation, etc. Good luck exploring this worthwhile topic and sharing it with us!

Johan Derycke said...

Interesting...
Why do you assume orange to be the hottest color. With this you state that a color has an absolute temperature. However, Michael and Bruce do have a point that a color's temperature is relative to it's surrounding colors.

I understand that this may stem from an urge to measure the difference in temperature between two hues, but why put it in an absolute value when you can just look at your subject and establish it by applying mixtures on your canvas? If one color you applied is too hot/cold you will notice and be able to adjust until you find the right temperature, no?

m.s.g. said...

Your "temperature" scale, is fascinating, and is a helpful tool, to understand the relative relationships between color. Very much the same way, that the Munsell Color System, establishes a scale for value and color. Question for you: in this particular study of purple, did you establish the temperature of your shadows, to be 'cooler' (cooler than the adjacent color temperature), and your light source to be warm? Do you ever switch that around, e.g. work with a cool north light, and use warmer shadows? Again, you raise some fascinating questions and concepts, with your temperature scale. Please keep posting your thoughts about this. fond regards to you and your family.

TC artist said...

I am very interested in seeing this worked out. The choice of red orange is correct as it is as much about psychology and physiology at work as it is physics. It seems that browns and grays can be quantified if there were 1 more variable included and then the entire scale renormalized so that red/orange came out to 100. Perhaps you already did that but simplified the extraneous math.

Pay Hell 1950 said...

We can see the engeneer here in that try....
Where is the artist???
Pierre Legendre

Michael Hunter said...

If you took all of the colors of a beautiful painting and rotated them 90 degrees on the color wheel the results would be horrendous. The colors would retain the same relationship but some other quality would be disrupted. (I tried this by the way.) Color relationships can be described mathematically but not our psychological reaction to color. Color wheels or color spaces or color solids – whatever you want to call the classification of color is helpful in discussing art but I’ve found it less helpful in predicting what colors to use because of the missing psychological component.
What I find so horribly difficult is this concept: A man from China makes paintings he thinks are beautiful and people in Texas agree. How can this be? Shouldn’t Chinese art be beautiful only to people who come from that culture? I live in the North-East of the US and I too think Mr. Qiang-Huang’s paintings are beautiful. I’ve never been to China. The psychological component is a basic human trait that is largely independent of cultural influences and even one’s own personal experiences. Otherwise no two people would like the same painting because no two people have the same experiences.
If you can put numbers to the psychological component then I think you have really achieved something of immense importance that goes far beyond art. This calls for a clinical study.
(In science cooler colors are hotter. White is 6500 Kelvin. Lower temperatures are yellow and red and infrared. Higher temperatures produce green, blue, violet and ultraviolet. Colors have also been classified by wavelength. Red is then 620 to 750 nanometers. It’s hard to imagine color as a distance isn’t it?)