It is hard to give an exact answer to this question, but in general one can say that the risk of using too many colors is greater than the risk of using too few.
Too many colors will make the page feel too busy and it usually makes it harder for the viewer to find the information he or she wants. It is also more tiring to the eyes.
A page with too few colors, on the other hand, risks being seen as a bit boring, but this need not always be the case.
One commonly used rule in these matters is to use three colors.
- Primary color: This is the main color of the page. It will occupy most of the area and set the tone for the design as a whole.
- Secondary color: This is the second color on the page, and it is usually there to "back up" the primary color. It is usually a color that is pretty close to the primary color.
- Highlight color: This is a color that is used to emphasize certain parts of the page. It is usually a color which constrasts more with the primary and secondary colors, and as such, it should be used with moderation. It is common to use a complimentary or split-complimentary color for this (see below).