A color code is used on resistors to indicate the resistance and the tolerance.
Axial lead resistors consist of a small cylinder with wire leads coming from both ends. Four colored rings are used for coding, with the first starting closer to an end than the fourth.
4 color rings:
(1) first significant figure
(2) second significant figure
(3) decimal multiplier
(4) tolerance
Color |
First Significant Figure |
Second Significant Figure |
Decimal Multiplier |
black |
0 |
0 |
10^0 = 1 |
brown |
1 |
1 |
10^1 |
red |
2 |
2 |
10^2 |
orange |
3 |
3 |
10^3 |
yellow |
4 |
4 |
10^4 |
green |
5 |
5 |
10^5 |
blue |
6 |
6 |
10^6 |
purple |
7 |
7 |
10^7 |
gray |
8 |
8 |
10^8 |
white |
9 |
9 |
10^9 |
Example: green-black-yellow indicates a resistance of 50 * 10,000 = 500,000 ohms
Tolerance colors:
(1) none: 20%
(2) gold: 5%
(3) silver: 10%
Specialty: Clinical Laboratory