The 150 ohm resistor color code is Brown-Green-Brown-Gold for standard 4-band (5% tolerance) components, and Brown-Green-Black-Black-Brown for precision 5-band (1% tolerance) components. If you are holding a 6-band resistor, the final band indicates the temperature coefficient, typically Brown (100 ppm/°C) or Red (50 ppm/°C).
Whether you are calculating current limits for a 5V LED circuit (where 150Ω yields exactly 20mA for a standard red LED with a 2V forward drop) or troubleshooting a faded component on a legacy PCB, this reference provides the exact decoding, standard variants, and concrete replacement part numbers you need.
The 150 Ohm Resistor Color Code Reference Table
The table below maps the exact color sequence for 150Ω across the three most common through-hole banding formats defined by IEC 60062. Read from left to right, starting from the band closest to the lead wire.
| Format | Band 1 (Digit 1) | Band 2 (Digit 2) | Band 3 (Digit 3 / Multiplier) | Band 4 (Multiplier / Tolerance) | Band 5 (Tolerance / Temp Co) | Band 6 (Temp Co) |
|---|---|---|---|---|---|---|
| 4-Band (5%) | Brown (1) | Green (5) | Brown (x10) | Gold (±5%) | N/A | N/A |
| 5-Band (1%) | Brown (1) | Green (5) | Black (0) | Black (x1) | Brown (±1%) | N/A |
| 6-Band (1%) | Brown (1) | Green (5) | Black (0) | Black (x1) | Brown (±1%) | Brown (100 ppm/°C) |
151 (15 x 10^1). For 1% precision SMD resistors using the EIA-96 standard, the code is 18A (18 = 150 base value, A = x1 multiplier).
Decoding the Bands: What Each Row Means in Practice
Understanding the math behind the colors prevents misreads when you are working quickly at the bench. The IEC 60062 standard assigns specific integers to colors, which are then combined with a multiplier.
- The Digits (Brown, Green): Brown represents 1, and Green represents 5. In a 4-band resistor, these form the base number 15.
- The Multiplier (Brown vs. Black): This is where the physical size of the resistor dictates the band count. In a 4-band resistor, the third band is the multiplier. Brown means
x10. Therefore, 15 x 10 = 150Ω. In a 5-band resistor, we need a third digit to represent the zero in 150. Black represents 0. The fourth band becomes the multiplier, which is Black (x1). Therefore, 150 x 1 = 150Ω. - The Tolerance (Gold vs. Brown): Gold indicates ±5% (meaning the actual resistance can range from 142.5Ω to 157.5Ω). Brown in the tolerance position indicates ±1% (148.5Ω to 151.5Ω).
Standard Variants: IEC 60062 vs. MIL-PRF vs. EIA-96
While IEC 60062 is the universal standard for commercial through-hole resistors globally, specific industries use variant coding systems that add extra bands or alter the reading direction.
| Standard | Application | 150Ω Identifier | Key Distinction |
|---|---|---|---|
| IEC 60062 | Global commercial through-hole | Brn-Grn-Brn-Gld (4-band) | Default standard; read left-to-right from bands closest to leads. |
| MIL-PRF-55342 | US Military / Aerospace | Brn-Grn-Blk-Blk-Brn-Color | Adds a 6th band for failure rate (e.g., Yellow = 0.001% per 1000 hrs). Do not confuse this with a temperature coefficient band. |
| EIA-96 | Precision SMD (1%) | 18A |
Uses a 2-digit lookup code (18=150) plus a letter multiplier (A=x1). Common on 0603 and 0402 footprints. |
Rows and Bands People Get Wrong
Even experienced technicians misread resistors under poor lighting or when components have degraded. Here are the specific rows in the color code chart that cause the most errors, and how to resolve them.
The most common mistake with 150Ω resistors is reading a 5-band (1%) resistor as a 4-band resistor. If you ignore the third band (Black/0) and read the fourth band (Black) as a 4-band multiplier, you will read Black as
x1 and assume the value is 15Ω. Alternatively, if you read the Brown tolerance band as a multiplier, you will calculate 15 x 10 = 150Ω, but miss the 1% precision rating. Always count the total number of bands before assigning digit vs. multiplier roles.
The Faded Green vs. Blue Problem:
Carbon film resistors subjected to prolonged heat (e.g., sitting next to a voltage regulator or power transistor) experience dielectric and pigment degradation. The Green band (5) often fades to a muddy teal or light Blue (6). If you misread the faded green as blue, you will calculate the resistor as 160Ω (Brown-Blue-Brown) or 140Ω (Brown-Yellow-Brown) depending on the shift.
Safe Interpretation Protocol:
Never guess a faded band. If the green band looks ambiguous, isolate the component. Desolder one leg to lift it from the PCB pad (preventing parallel circuit paths from skewing your reading) and measure it with a digital multimeter (DMM) using the 200Ω or 2kΩ range. A reading between 148Ω and 152Ω confirms a 150Ω 1% part; a reading between 142Ω and 158Ω confirms a 150Ω 5% part.
Decision Path: Selecting the Right 150Ω Replacement
When your 150Ω resistor is burnt open or out of spec, do not just grab any 150Ω component from your bins. The wrong material composition will fail prematurely or introduce noise into sensitive circuits. Use this decision tree to select the exact replacement part.
| Circuit Application | Required Spec | Concrete Part Pick (2026) | Why This Part? |
|---|---|---|---|
| LED Current Limiting / Digital Logic Pull-ups | 1/4W, 5%, Carbon or Thick Film | Yageo CFR-25J150R | Cheap, abundant, handles standard 5V/3.3V logic currents without thermal drift issues. |
| Audio DAC / ADC Filtering / Op-Amp Feedback | 1/4W, 1%, Metal Film, Low Noise | Vishay MRS25000C1500FCT00 | Metal film eliminates the current-dependent noise of carbon; 50ppm/°C tempco keeps analog gains stable. |
| Snubber Networks / High Surge / Motor Drivers | 1/2W or 1W, Anti-Surge, Pulse Rated | KOA Speer RK73H2ATTD1500F | Thick film anti-surge design absorbs inductive kickback spikes that would crack standard thin-film resistors. |
Final Bench Rule: If you are replacing a 5-band (1%) metal film resistor in an analog signal path, never substitute it with a 4-band (5%) carbon film resistor, even if the nominal 150Ω value matches. The 5% part will introduce thermal noise and shift the circuit's bias point outside its designed operating window. Always match or exceed the original tolerance and power rating.
