Let’s talk about color. To begin with, what we see as color are different wavelengths of light. Light in turn is part of the electromagnetic spectrum. What we see of the different wavelengths of light is referred to as the visible spectrum. White and black, while technically considered colors, are not part of the color spectrum. What we see as “white” is actually the combination of the different wavelengths of light. Black is an absence of white. (Both white and black also come into the picture as “value” or “brightness” which indicates how bright or dark a color is.)
There are two methods of combining colors. In the additive method, differing amounts of red, green and blue light are combined to create new colors. This method is the most relevant to web designers because that is how computer monitors produce color. The other method is known as the subtractive method. With this method, different colors are produced by removing wavelengths from white light. (The subtractive method is the most relevant to print and painting.)
Some additional terminology that is useful to know:
RGB: Red, green, blue. Computer graphics will generally be in the RGB format.
CMYK: Cyan, magenta, yellow, black. Printers use this method for combining colors. If you are creating graphics that will be used in both print and on the web, you should make sure that you convert the graphics you are going to print to CMYK.
Hue: This refers to the wavelength of a color. Red, yellow, blue, purple, as an example.
Saturation: This is the level or intensity of a color.
Gamut: This refers to the spectrum of colors available to use in a specific medium.
Temperature: It is somewhat helpful to think of colors as being either “warm” or “cool.” Colors that tend to seem warmer are shades of red and yellow. Colors that tend to seem cooler are shades of green, blue and violet. These different color temperatures can suggest different moods.
Symbolic Color: Some colors have different symbolic and metaphorical meanings attached to them. You can feel blue and be green with envy.
Having a general idea of how color works, and the terminology related to working with color is something that is useful for the designer to know. (It is also something that is useful to know if someone else is designing the site for you. That way, you can ask the designer questions and you will understand the answers.)