The three primary colors of light are red, green, and blue (RGB). Combinations of these building blocks can be used to produce all of the colors in the visible spectrum, and equal amounts of all three produce white light. Because these colors are added together to make white, they are known as additive primaries. Mixing equal amounts of two primary colors together produces what are known as the secondary colors. These are: yellow (red + green); cyan (green + blue); and magenta (blue + red). The easiest way to visualize these relationships is using a diagram known as a color wheel.

By placing the different colors around a circle you can see how the colors work, and how they influence each other. The primary colors are equally placed around the wheel, with the secondary colors placed between the two colors that, when combined, make that color.

The colors that are next to each other on the color wheel are known as harmonious or analogous colors. This is because when you see them together they give a sense of calm and peace, or harmony. Colors opposite each other on the color wheel create the maximum contrast and are known as complementary colors. When viewed together, these colors can clash, creating a striking image. These two relationships between colors lie at the heart of color theory. Color theory has been used by both scientists and artists for centuries, allowing them to categorize colors, or exploit them for visual effect.

By Chris Rutter, “Color Theory Fundaementals for Digital Photography”