This landscape study is an example of using different colors purely as values to prove that it is value, not color, that creates dimensionality in a painting. Pastel is a great medium for this experiment, start by picking one dark value color, one middle value color and one light. They should not be the same color, in other words, don’t pick 3 values of blue to create a monochromatic drawing, instead, vary the colors, but be sure to pick 3 distinct values.
In this example, I’ve used a dark blue-green, a middle value rust and a light salmon pink. Begin by mapping in the dark values with the darkest color. Add in the mid tones with a lighter touch, still using the dark color. Then switch over to the middle value color and go over the areas you have mapped out as mid tones. Last of all, add in your brightest brights with the lightest of the 3 colors. Regardless of your color choices, you should get a realistic, 3 dimensional result as long as the values you selected represented a dark, middle and light tone. Try it, it’s an interesting experiment that will convince anyone who is not sure about the relationship of value and color that value is the determining factor in making an image appear 3D. It will also force you to focus on moving around your composition if you block in one value at a time, rather than finishing one area before moving on to the next.