The resistance color code is a visual marking system defined globally by IEC 60062 to indicate the ohmic value, multiplier, and tolerance of axial-leaded resistors. You read the bands left-to-right, with the tolerance band (usually gold or silver) spaced slightly apart on the far right. Below is the complete master reference table, followed by standard variants, common bench misreads, and a strict decision path for damaged components.
The Master Resistance Color Code Reference Table (IEC 60062)
This table applies to all standard 4-band, 5-band, and 6-band axial resistors. The "Digit" column applies to the first two bands (4-band) or first three bands (5/6-band). The "Multiplier" applies to the band immediately following the significant digits.
| Color | Digit (Significant Figures) | Multiplier (Band 3 or 4) | Tolerance (Band 4 or 5) | Temp. Coefficient (Band 6) |
|---|---|---|---|---|
| Black | 0 | ×1 (10⁰) | — | 250 ppm/°C (U) |
| Brown | 1 | ×10 (10¹) | ±1% (F) | 100 ppm/°C (S) |
| Red | 2 | ×100 (10²) | ±2% (G) | 50 ppm/°C (R) |
| Orange | 3 | ×1k (10³) | — | 15 ppm/°C (P) |
| Yellow | 4 | ×10k (10⁴) | — | 25 ppm/°C (Q) |
| Green | 5 | ×100k (10⁵) | ±0.5% (D) | 20 ppm/°C (Z) |
| Blue | 6 | ×1M (10⁶) | ±0.25% (C) | 10 ppm/°C (M) |
| Violet | 7 | ×10M (10⁷) | ±0.1% (B) | 5 ppm/°C (K) |
| Grey | 8 | ×100M (10⁸) | ±0.05% (A) | 1 ppm/°C (L) |
| White | 9 | ×1G (10⁹) | — | — |
| Gold | — | ×0.1 (10⁻¹) | ±5% (J) | — |
| Silver | — | ×0.01 (10⁻²) | ±10% (K) | — |
Source reference: All About Circuits - Resistor Color Codes and IEC 60062 standard mappings.
Standard Variants: Commercial, Military, and Precision
While IEC 60062 governs commercial resistors globally, you will encounter specific variants depending on the equipment you are servicing or building.
| Variant | Band Count | Standard / Spec | Typical Application |
|---|---|---|---|
| Standard Commercial | 4-Band | IEC 60062 | General purpose, 5% carbon or metal film (E24 series). |
| Precision Commercial | 5-Band | IEC 60062 | 1% or better metal film, tight feedback loops (E96 series). |
| High-Stability | 6-Band | IEC 60062 | Adds Temperature Coefficient of Resistance (TCR) band for precision analog/RF. |
| US Military (MIL-SPEC) | 5-Band | MIL-PRF-55182 | First 3 bands = digits, 4th = multiplier, 5th = failure rate (e.g., M=1%, P=0.1%). Tolerance is baked into the spec sheet, not color-coded. |
The "Rows People Get Wrong" Field Notes
On the bench, theoretical color charts fail under poor lighting or with aged components. Here are the specific rows and scenarios that cause misreads, and how to correct them.
1. Brown (1) vs. Red (2) Under Warm Lighting
Under 2700K-3000K warm-white bench LEDs, the red pigment in older carbon-film resistors absorbs light and looks identical to brown. The Fix: Always use 5000K cool-white lighting for component identification. If you are stuck with warm light, look at the very edge of the band where the paint is thinnest; red will show a distinct crimson hue, while brown remains muddy.
2. The Gold/Silver Multiplier Trap
Most hobbyists memorize gold as 5% tolerance and stop thinking about it. But in the multiplier position (Band 3 on a 4-band resistor), Gold means ×0.1 and Silver means ×0.01.
Example: Yellow (4), Violet (7), Gold (×0.1), Gold (5%). This is a 4.7Ω resistor, not 470Ω. Misreading this in a current-sense application will blow your shunt.
3. Reading 5-Band Resistors Backwards
Manufacturers sometimes print 5-band resistors with uniform spacing, making it unclear which end is the start.
The Fix: Check the first band against the E24/E96 standard values. If reading left-to-right gives you "Orange, Orange, Black, Red, Brown" (33kΩ, a standard E24 value), but reading right-to-left gives "Brown, Red, Black, Orange, Orange" (120kΩ, also standard), look for the physical gap. The tolerance band (Brown = 1%) will almost always have a slightly wider physical gap between it and the multiplier band. For a deep dive on physical spacing cues, refer to DigiKey's technical guide on resistor markings.
Decision Path: Identifying Faded, Burnt, or Unmarked Resistors
When a resistor has been subjected to thermal stress, the epoxy coating darkens, and the color bands blister or fade. Do not guess. Use this decision tree to determine your next action.
| Condition Observed | Diagnostic Action | Terminal Decision / Concrete Pick |
|---|---|---|
| Bands are legible, but one is ambiguous (e.g., Red vs Brown). | Measure in-circuit with a DMM. Compare reading to standard E24/E96 values. | Keep. If DMM reads ~2.2kΩ, the ambiguous band was Red (2). If it reads ~1.2kΩ, it was Brown (1). |
| Resistor body is scorched/blackened, but bands are barely visible. | Measure in-circuit. If reading is open (OL) or >20% off expected standard value. | Replace. Desolder and replace with a Vishay MRS25 series 1% metal film resistor of the nearest standard E96 value. Do not reuse heat-damaged carbon film. |
| Resistor is completely unmarked (blank tan/blue body) or bands are 100% gone. | Desolder one leg to isolate from parallel PCB traces. Measure with DMM. | Bin or Replace. If it measures within 5% of an E24 value, label it and reuse in non-critical circuits. If it's for a precision analog stage, bin it and install a new Bourns MF-R series part. |
| Component is a tiny cylinder with no color bands, only printed text (e.g., "103"). | Recognize this is not an axial color code; it's a 3-digit SMD/jumper code printed on a MELF or axial body. | Interpret as SMD. "103" = 10 × 10³ = 10kΩ. Treat the first two digits as significant, third as multiplier. |
Safe Interpretation and Component Derating
When you cannot definitively read a resistance color code, safety and circuit reliability must override the desire to save a $0.02 component. A faded resistor is a resistor that has operated at or beyond its thermal limits.
If you are designing a board or replacing a burnt component in a high-temperature environment (like inside a tube amplifier chassis or a power supply enclosure), do not rely on standard 1/4W carbon film. Step up to a 1/2W or 1W metal oxide film resistor (such as the Xicor or Yageo FMP series). Metal oxide handles surface temperatures up to 155°C without the epoxy charring, ensuring the color bands remain legible for the next technician who has to troubleshoot the board a decade from now.
Ultimately, the color code is a secondary verification. Your digital multimeter, set to the correct range and zeroed, is the final authority on what a resistor will actually do in your circuit.
