Color theory--despite the connotations of the word "theory"--is actually very simple. So simple, in fact, that you probably already know it, understand it, and use it on a daily basis. The term "color theory" is used to describe the rules and guidelines regarding the use of color in art and design, but more broadly, we use color theory numerous times a day, every single day, without really considering it "theory." We choose colors that match or look good together when we get dressed (unless, of course, like me, you only wear black or shades of gray!). We even choose our clothes based on our moods, the seasons, or special occasions. And that is color theory--the idea that certain colors go together, certain colors don't, and that colors have personalities or can evoke emotions. That's it!
But let's dig a little deeper and break it down a bit from the color wheel to the emotions because there are a few things about color theory that are essential for artists:
1. Color mixing to create a wide spectrum of colors from a basic palette
2. Creating color schemes
3. Conveying emotions through color
To get a better grasp of those things, trial and error is key. As artists, we need to actually mix our paints and experiment to see what works for us, but understanding the color wheel and color theory will certainly make it easier!
Starting from square one, the basic ideas of color theory are based entirely on the color wheel, which was invented by Sir Isaac Newton (the apple on the head guy). With the color wheel, we can see clearly how the primary colors--red, blue, and yellow--can be mixed to create secondary colors--purple, green, and orange. But your 5 year old self already knew that! ;-)
Beyond secondary colors are intermediate and tertiary colors that can be created by combining primary and secondary colors in varying ratios. Although many people use the terms intermediate and tertiary interchangeably, they are actually quite different. Intermediate colors are created by mixing uneven amounts of two primary colors OR by mixing a primary with a secondary next to it on the color wheel. Depending on how much of each primary is in these mixtures, the results can be a yellow-green or a blue-green, a blue-violet or a red-violet. A tertiary color is created by mixing two secondary colors. For example, a tertiary color can be achieved by combining green and violet, which is actually a combination of THREE primary colors--2 parts blue with 1 part yellow and 1 part red. However, it's very important to note that the terms intermediate and tertiary are used interchangeably, and most often, you will find intermediate colors being referred to as tertiary colors.
A painter's color wheel won't give you the entire spectrum of colors, but we've all probably seen color wheels on a computer screen that do just that--give us a full spectrum of colors to choose from:
The color wheel helps demonstrate one very important aspect of color theory: color schemes. According to color theory, generally speaking, harmonious color combinations use 2-4 colors evenly spaced around the color wheel from one another: complimentary, or opposite (forming a straight line), triadic (forming a triangle), or tetradic (forming a square or rectangle). Another basic color scheme is analogous, or colors situated next to each other on the color wheel.
There are variations of each of these color schemes, and again, as artists, it's necessary to experiment, but when choosing color schemes for your paintings, these three color scheme theories are the most commonly used. It's also important to note that artworks are rarely limited to only a specific color scheme! Think of color schemes as your base coat/the broad strokes. From there, you'll add many more layers of colors to add details and depth to your work. And this is, of course, not to say that you can't create something beautiful with just 2-3 colors!
The analogous color scheme uses colors that are next to each other on the color wheel. One color is used as a dominant color, while others are used to enhance the scheme. For example, if red is chosen as the dominant color, pinks and/or oranges would be used to enrich the dominant color.
The complementary color scheme uses two colors that are opposite each other on the color wheel. This scheme is intrinsically high-contrast as it pairs a warm color (reds, oranges, or yellows) with a cool color (greens, blues, or purples, respectively).
Triadic color schemes are the most popular among artists because it provides a strong visual contrast of colors while retaining color richness and harmony. It's not as contrasting as the complementary scheme, so it contains a better balance of colors.