Mixing colors can be a challenge at the beginning. It's sometime challenging to know how to mix a particular skin tone for example. The best way to start learning about how to mix colors is to analyze them.
There are three main areas to analyze in mixing color that you have probably heard used and not completely known what they mean. They are known as the properties of color: Hue, Intensity and Value.
HUE: Describes the actual color of an object or substance.
PRIMARY COLORS: Red, yellow, and blue. These colors cannot be produced by combining other colors.
Unlike humans, birds are tetrachromats. Their four types of cone cells let them see red, green, blue, and ultraviolet together.
To mix a color you first identify its Hue. This is done by using the color wheel as a reference.
The first step in mixing color is to classify the color. There are six main groups from which to choose. Yellow, Blue, Red, Orange, Green and Violet. The remaining colors are variations of Orange, Green and Violet with a shift towards one of the primary colors.
The Primary Colors are: Yellow, Blue and Red. These are considered primary because all other colors are derived from these when you mix two primaries together.
The Secondary Colors are: Orange, Violet and Green. These mixtures are achieved when you add two of the primaries together.
Yellow + Red = Orange
Red + Blue = Violet
Yellow + Blue = Green)
INTERMEDIATE COLORS: Red-orange, yellow-orange, yellow-green etc. As each name indicates, an intermediate color is produced by combining a primary and a secondary color. Intermediate colors are located between primary and secondary colors on the color wheel. Two primary colors can produce an intermediate color also.
The intermediate Colors are: Yellow Green, Blue Green, Yellow Orange, Red Orange, Red Violet and Blue Violet. These mixtures are derivatives of the secondary colors and are achieved by mixing more of the primary colors.
Green+Yellow = Yellow Green
Green+Blue = Blue Green
Violet +Blue = Blue Violet
Violet + Red = Red Violet
Orange+ Red = Red Orange
Orange + Yellow = Yellow Orange
All together these represent the twelve Hues or colors on the Color Wheel.
INTENSITY: The saturation or strength of a color determined by the quality of light reflected from it. The brightness or purity of a color. A pure color is in its brightest form and is most intense. The addition of any color lowers the intensity.
The next step in analyzing color is determining its intensity.
In other words, is the color you're looking at vivid or dull when comparing it to it's spectrum color? If it's duller, then it's considered to be of lower intensity.
If the color is very bright and vivid, then it's of a high intensity.
To lower a color's intensity you add it's complement (which is opposite on the color wheel) in small amounts until you've achieved the right degree of dulling so to speak. Since you are mixing opposites, it also means you're mixing a warm color with a cool color.
Any color that is of a lower intensity contains all three primaries in the mixture.
For example. Yellow+Blue=Green which contains 2 primaries. The primary color left over is Red. Thus, red is the complimentary color of green and vice versa. Let's take one more example, the primary color yellow. What is it's compliment? Well, what are the other primaries? Blue and Red. What do you get when you mix these? Violet. That's the compliment of yellow and when violet is mixed with yellow it will dull it's intensity and vice versa.
VALUE: Value refers to the lightness or darkness of a color. It indicates the quantity or light reflected. Adding black, white, or gray to a color changes its color value.
TINT: The addition of white to a color.
TONE: The addition of gray to a color.
SHADE: The addition of black to a color.
To lighten a color's value also known as a tint, add white. To darken or lower the value also known as a shade, add black. In some cases however it's better to use a related darker oil paint such as when you want to darken a yellow.