Resistor Color Code
Decode resistor color bands or find colors for a resistance value. Common in electronics-themed puzzles.
1st
brown
2nd
black
×
red
±
gold
Resistance Value
0.00 mΩ
±5%
1st Digit
1
2nd Digit
0
Multiplier
×100
Color Code Reference
black = 0
brown = 1
red = 2
orange = 3
yellow = 4
green = 5
blue = 6
violet = 7
gray = 8
white = 9
What is Resistor Color Code?
Resistor color code is a system of colored bands printed on resistors to indicate their resistance value. Each color represents a digit (0-9) or a multiplier, allowing technicians to quickly identify resistor values without measuring equipment.
How to Read Resistor Colors
For a 4-band resistor (most common):
- 1st band: First significant digit
- 2nd band: Second significant digit
- 3rd band: Multiplier (power of 10)
- 4th band: Tolerance (accuracy)
Color Values
| Color | Digit | Multiplier |
|---|---|---|
| Black | 0 | ×1 |
| Brown | 1 | ×10 |
| Red | 2 | ×100 |
| Orange | 3 | ×1,000 |
| Yellow | 4 | ×10,000 |
| Green | 5 | ×100,000 |
| Blue | 6 | ×1,000,000 |
| Violet | 7 | ×10,000,000 |
| Gray | 8 | ×100,000,000 |
| White | 9 | ×1,000,000,000 |
| Gold | — | ×0.1 |
| Silver | — | ×0.01 |
Mnemonics
Common memory aids for the color sequence:
- Bad Beer Rots Our Young Guts But Vodka Goes Well
- Black Brown Red Orange Yellow Green Blue Violet Gray White
Resistor Color Code in Geocaching
This encoding appears in geocaching puzzles because:
- Electronics theme: Common in tech-themed caches
- Color puzzles: Colors map to numbers
- Physical clues: Actual resistors can be placed at waypoints
- Educational: Teaches electronics basics
Example
A resistor with bands: Brown, Black, Red, Gold
- Brown = 1 (first digit)
- Black = 0 (second digit)
- Red = ×100 (multiplier)
- Gold = ±5% (tolerance)
Value: 10 × 100 = 1,000 Ω (1 kΩ) ±5%
5 and 6 Band Resistors
Precision resistors may have more bands:
- 5 bands: Three digits + multiplier + tolerance
- 6 bands: Adds temperature coefficient band