Resistors are devices, which are used to limit current flow and provide a voltage drop in electrical circuits.
With small size physically, the resistors are marked with color coded bands that have a different number per color, as well as the tolerance of the Resistors in series. The use of color bands on the body of a resistor is the most common system for indicating the value of a resistor. Color-coding is standardized by the Electronic Industries Association (EIA).
Resistor Color Code Calculator is used to understand how to use the color code system. The general purpose carbon film resistors which are used in electrical and electronic circuits are
marked using a four colored bands system. The 4th color band indicates the resistor’s tolerance
and is normally gold. This means that the resistor is within 5% plus or minus of the marked
value. A silver 4th color band indicates a 10% tolerance. The first three bands determine the
value of the resistor. The first two bands determine the value of the resistor and the third band
determines the multiplier for the first two digits. Simply stated, the value of the third band
determines the number of zeros to add to the first two color values.