24
Understanding Resistor Color Codes
The following experiments use three resistors; however, since the value of the resistor is
not stamped on the device, another method is used to identify its value. This method is
called “color coding” and refers to the round bands that surround the resistor’s cylindrical
surface. The following is the number and corresponding color convention for identifying
color codes.
0 – Black
1 – Brown
2 – Red
3 – Orange
4 - Yellow
5 – Green
6 – Blue
7 – Violet
8 – Gray
9 - White
For example, a 4,700-ohm resistor would have the following color codes (stripes)
beginning at the far end of the device.
4,700 ohms = Yellow (4) – Violet (7) – Red (2)
The last stripe (Red = 2) is a multiplier of 10 raised to the power of the stripe value, as in
10
2
which equals 100. Therefore, we get 47 x 100 = 4,700 ohms. Our three resistors
have values of 1 ohm, 10 ohms and 20 ohms with the corresponding color codes…
1 ohm =Brown (1) – Black (0)
(A multiplier of 10
0
= 0)
10 ohms = Brown (1) – Black (0) – Black (0)
(A multiplier of 10
0
= 0)
20 ohms = Red (2) – Black (0) – Black (0)
(A multiplier of 10
0
= 0)
