My first experiments mixing red and green were with pan watercolors in elementary school. We mixed green and red to get brown. The result was a kind of muddy mess. I remember the effort I put in trying to keep the yellow and the other colors from becoming a muddy mess, too. Pan watercolors were based on spectrum colors. Isaac Newton’s experiments with prisms in the 1600s revealed the seven spectrum colors: red, orange, yellow, green, blue, indigo, and violet, which led to the color wheel. But it was Christoph Le Blon in 1725, who came up with the idea that all colors could be created by using three "primitive" or primary colors. He called his invention "Printed Paintings" and used three intaglio plates to get a wide range of colors. It sounds very similar to todays "RGB" color printers.
One theory is that human vision is trichromatic. That is, vison receptors convert red, green, and blue colors into all the colors we see. Each color has a different wavelength. The shortest wavelength is blue, the medium wavelength is green, and the longest wavelength is red. Most humans can easily distinguish red and green. Did early humans develop this way of seeing to find the ripest fruit or to tell when other humans were embarrassed or angry?
Artist's acrylic colors are generally not the same as spectrum color. This can be confusing to beginners. There are so many possibilities available from pre-mixed colors to professional artist colors with names like Phthalocyanine Green. Each color has its own history. The umbers are some of the oldest known colors. Quinacridone colors became available in the late 1950s.
My goal was to see if mixing green and red would give me an interesting range of greens. I also wanted to create a gray by mixing the complementary colors green and red. I was checking to see if that gray provided a more interesting look than one mixed with black and white, or using a tube of gray paint. I also wanted to avoid the red and green combinations that symbolize the Christmas season in our culture.
Colors: Quinacridone Crimson, Quinacridone Nickel Azo Gold, Hooker’s Green Hue Permanent, Phthalocyanine Green, Cadmium Yellow , Burnt Umber, Titanium White
I found the combination of Phthalocyanine Green and Burnt Umber works a lot like Ultramarine Blue and Burnt Umber, which is a handy combination to rough tonal parts of a composition before adding other colors. Phthalocyanine Green has a wide tonal range. Here, I used a light wash to represent the blue sky. The mixed gray seemed to have a more reddish look than I liked, but it still worked fairly well.
Colors: Quinacridone Crimson, Cadmium Red Medium, Quinacridone Nickel Azo Gold, Cadmium Yellow, Burnt Umber, Titanium White
This was taken from a photograph of a glass sculpture created by Robert Kuster of Belle Mead Glass for Virginia Beach Joint Use Library. I added Cadmium Red Medium and removed Hookers Green. I wanted to see what green would do with deep reds. First, I did some swatches to see if this would give the desired result. The colors: Quinacridone Crimson, Cadmium Red Medium, Quinacridone Nickel Azo Gold gave me a nice range of reds golds and oranges. Again, I used Phthalocyanine Green as a light wash to represent the blue sky.
Colors: Here I used all the colors in my limited palette.
After the other two tests, I was double or triple mixing my colors. I don’t set up a palette with all my colors on it at once. That leads to waste because the paint dries out. I focus on mixing one color at a time and putting the most valuable ones in sealed recycled containers. An example: once I mixed a red, green, and umber that was close to black. I kept it to mix later with the other colors. I was delighted that Phthalocyanine Green and Quinacridone Crimson mixed to give me the reddish purple or imperial purple seen in the Radicchio.
These tests have given me a new appreciation of Phthalocyanine Green. I am not sure if this warmer color palette gives a different emotional feel to the paintings. Careful color mixing can give very interesting results. I do miss having blue in my line up of colors.