Monday, December 27, 2010

Color Mixing and Color Wheels

I was working on a poem tonight and I wanted to know how an orange-hued sunset might affect something that was the color blue. I suspected that the resulting color would be some variation on brown, but I wanted to see it for myself. Since it was too late in the day for a nice sunset, I searched online for color wheels. They were so much fun to use, and I learned so much about color, that I thought I would share my findings with you.

Mixing Colors

This Online Color Mixing Palette for Painters from is easy to use. Just click the colors to add them to the mixing bowl and see what happens. If you want to examine, say, two parts blue to one part red, click on the blue square twice and the red square once. The counter keeps track of how many "parts" you've added of each primary color.

COLORCUBE's Color Paintbox is a bit trickier to use. What I liked about this simulation is that you are mixing colors other than the three primary colors of red, blue, and yellow. Instead, your tubes of online mixing paint are white, black, cyan, magenta, and yellow. With effort, you can mix the paint to create any shade along the COLORCUBE. It takes some practice to achieve the color you want!

Made From Dots, from the Teachers' Lab's The Science of Light pages, explores the same theme as COLORCUBE and explains the reasoning behind these choices for mixing colors:
"A magazine printing press usually can only print four colors: Cyan, Magenta, Yellow, and Black. Our eyes and brain put colors together from the colored dots. Printers (and the computers they use to help them) print the dots in special grids that do not overlap."
Made From Dots shows you what different percentages of cyan, magenta, and yellow saturation look like when they overlap and how our brain perceives the resulting mixture of dots. I found it challenging at first to predict the resulting colors, but it became easier the longer I practiced.

However, keep in mind that mixing colors online is different than mixing them in real life. For example, if you mix every drop of paint in the rainbow of oils on your palette, you will create a blob of blackish paint for your canvas. This is known as the subtractive color method. You start with a white page and end up with a darker mixture of paint.

Online, however, you start with an essentially black screen. Colors are mixed on the computer using the additive color method and you wind up with a lighter image than what you began with. You can read more about additive and subtractive color methods at Janet Lynn Ford's Color Worqx pages.

Color Wheels

Color wheels can be fun to make. Little Brother made one in preschool using a sheet of heavy-duty construction paper, a straw, and a pin. His wasn't a full color wheel, but just two alternating colors of red and yellow. When you spun the wheel, the whole thing looked orange.

Here's a lovely COLORbasics segment from Lisa Viger on painting a color wheel:

According to numerous web sources, including Home Science Tools, if you punch a hole through the middle of a real color wheel and spin the thing fast enough, all of the colors seem to disappear and the wheel will look white. The logic behind this is that white light is a mixture of all of the colors of the spectrum. (But it is still hard to fathom!)

After poking around on YouTube for awhile, I've come to the conclusion that while this result is true in theory, it's difficult in real life to get your color wheel spinning fast enough for the effect to work. According to the Physics Archive at Argonne National Lab's NEWTON Ask a Scientist, Vince Calder wrote that "the color wheel must rotate quickly enough so that each color segment superimposes the other two in 1/25 of a second or less."

Do you have any fun experiences to share about color or color wheels? Let me know in the comments.

Enjoy a colorful day!


Don Jusko, Artist on Location said...

I'm sorry that I'm bad at posting.
Regarding the Real Color Wheel,

There is a 3RCW, 6RCW, 12RCW, 36RCW and a 360RCW. The 3RCW can spin easily by hand to show white. The 36RC would have to spin 36 rotations in the time it took the 36RCW to make one rotation. Try an electric drill with the glued colorwheel on a bit.

Don Jusko, Artist on Location said...

And even that time I forgot to mark the check-box to get follow-up comments. Which is the reason for this post.

jublke said...

Hi Don: No worries! Thanks so much for your comments. Love the idea of spinning a color wheel on an electric drill! You've done some incredible work on color wheels. Here's a link to Don's Real Color Wheel.