Color Theory 101, I had to take it my first year of design school. Granted it was a fun and easy class filled with craft projects that resembled the one's you made for mom and dad when you were 4. But hidden underneath the craft projects was a philosophy/psychology class that begged you to ask "How RED is this red?".
Before I get ahead of myself, let's start by talking about the color wheel.
Comprised of 12 colors that can be broken down in a number of ways, but we will just stick to the 3 most common.
Primary Colors: yellow, red and blue. You remember them, right?
Secondary Colors: orange, purple and green; colors created by mixing a PRIMARY with it's PRIMARY neighbor. (yellow+red=orange, red+blue=purple, blue+yellow=green)
Tertiary Colors: colors created by mixing the PRIMARY and SECONDARY. (yellow+orange=yellow-orange, red+orange+=red-orange. The marriages go on and on to create red-violet, blue-violet, blue-green, yellow-green.)
Now that we have refreshed ourselves on the basic color wheel, let's see what we can come up with when we get a little creative.
Monochromatic: use of 1 color that varies from light to dark or in other words saturation.
Here is an example of how color wheels represent saturation.
Complimentary: use of 2 colors on opposite ends of the color wheel.
(Red & Green/Pink & Lime)
Triadic: use of 3 colors that create a triangle on the color wheel.
(Red, yellow, blue)
Analogous: use of 3 or more colors next to each other on the color wheel.
(I know the graphic only shows 2 colors but 3 always looks better).