As you have learned earlier, the last color band of the resistor represents the resistor tolerance. Resistor tolerance is defined as the spread in the value of resistor with reference to its designated resistance value. It is very difficult to make a resistor with exact resistance value that is why resistors contain tolerance to approximate the value of resistor.
December 8, 2008
Resistors may contain three to five color bands. Resistors with +20% tolerances contain only three color bands. Four color bands are usually printed on the body of most resistors. For a resistor with four color bands, the first color represents the first significant figure. The second color band represents the second significant figure. The third color band is the multiplier and the last color band is the tolerance. Below are the lists of colors with their corresponding values when used as significant figure, as multiplier and as tolerance.
tags: Resistor Color Code