My lack of color knowledge slowed me down in the introductory painting classes I just finished. There was some discussion in class about mixing, but the palettes we used were limited to just a few colors. I realized the only way around the problem was to pick some colors for a starter palette and do some color charting. Since I just finished reading Alla Prima, which has a good chapter on color, that seemed like a reasonable place to start.
Richard Schmid claims he can mix most other commercially-available tube colors from a palette of 11 colors which includes 4 yellows (cad lemon, cad yellow pale , yellow ochre pale, cad yellow deep), 4 reds (cad red, alizarin permanent, terra rosa, transparent oxide red), a green (viridian), and 2 blues (cobalt light, ultramarine). I like the idea of learning to mix with a set number of choices.
Schmid describes how to prepare the charts in detail in his book. Briefly, I gessoed a dozen 8" x 15" pieces of heavy illustration board, taped off 5 rows x 11 columns of 1" squares with 1/4" masking tape, then mixed and applied the colors. Each board represents a predominant hue mixed with a smaller amount of each of the other hues. Each of these mixtures is then combined with white to produce 5 graduated values. It took about 3 hours per chart.
I took my time and tried to spot the similarities and differences between colors within each family; made mental notes on how to mix common hues; noted the shift in hue of a color combination as one color predominated, then the other. It was really exciting to pull the tape off the finished charts. They're gorgeous in real life. I felt like I was printing money, generating this wealth of beautiful colors. I didn't post the individual charts here because the reproductions are so inferior to the real thing, but if you click on the group image above you get an idea of the color diversity. The upper left chart shows the gradations of the original tube colors.
I mounted the charts on the wall near my easel for easy reference. A good exercise is to pick a color in the surroundings, name the combination of 2 tube colors to arrive at that color, then check that guess against the charts. Only 2 tube colors per mixture to avoid the mud. Also, if you haven't yet, take a look at David Rourke's discussion on color mixing in his blog, All The Strange Hours. Finally, Bruce MacEvoy offers a complete discussion of color at his blog Handprint, with some useful value and color mixing charts (TY to David for mentioning Handprint).