Complementary colors are colors that are located directly across from each other on the color wheel. Color relationships or color schemes are just one small part of color theory in general. (To learn more about color theory visit here-> Color Theory) Using color schemes in a design, like for example a logo is pretty straight forward. Color theory in representational artwork, however can be a little more challenging. One way to use color theory, specifically complementary colors, in representational artwork is to consider highlights and shadows. Highlights and shadows define the illusion of the form. When we are creating drawings or paintings, we are dealing with illusions. Light is defined by the position of the highlights and the shadows. In turn, the highlights and shadows define the form, completing the illusion. Highlights and shadows are opposites. Complementary colors are also opposites. If we include complementary colors in the highlights and shadows of our drawings and paintings, we not only add contrast, but we also add color interest. This increases the visual appeal of our artwork.
You can add the fact that shadows are naturally blue in hue, and that the actual colors of the object matter (local color). This means that one could argue that highlights and shadows are actually a blend of blue, local color, and complementary colors. Try it out in your paintings and drawings and see if you notice a difference. Work in layers to create a blue shadow, layered local color, and intensify it with complementary colors.
To learn more about using complementary colors to create visually stimulating highlights and shadows and to see the video demonstration click here-> How to Use Color Theory in Highlights and Shadows