The direct answer for a standard 6.8 kΩ (6800 ohm) resistor is a 4-band code of Blue, Grey, Red, Gold. If you are holding a precision 5-band resistor, the code is Blue, Grey, Black, Brown, Gold. The value 6.8 is a standard base number in the E24 preferred value series, meaning you will frequently encounter it in voltage dividers, LED current-limiting circuits, and pull-up networks.
Because bench lighting and manufacturing variances can make color bands notoriously difficult to read, relying solely on visual inspection is a common source of debugging headaches. Below is the exact breakdown of how this value is encoded, the standards that govern it, and how to verify it when the paint is faded.
The 6.8 k Ohm Resistor Color Code Reference Table
The following table maps the exact color bands to their numeric equivalents for 6.8 kΩ across different resistor formats. Use this as your primary bench reference.
| Band Position | 4-Band (Standard 5%) | 5-Band (Precision 1%) | 6-Band (High Precision) | Meaning / Multiplier |
|---|---|---|---|---|
| Band 1 (Digit 1) | Blue | Blue | Blue | 6 (First significant digit) |
| Band 2 (Digit 2) | Grey | Grey | Grey | 8 (Second significant digit) |
| Band 3 (Digit 3 / Mult) | Red | Black | Black | 4-Band: ×100 | 5/6-Band: 0 (Third digit) |
| Band 4 (Multiplier / Tol) | Gold | Brown | Brown | 4-Band: ±5% Tol | 5/6-Band: ×10 Multiplier |
| Band 5 (Tolerance / Tempco) | N/A | Gold (or Brown) | Gold | Tolerance (Gold = ±5%, Brown = ±1%) |
| Band 6 (Tempco) | N/A | N/A | Brown (or Red) | Temperature Coefficient (e.g., 100 ppm/°C) |
| SMD Equivalent (3-digit) | 682 (68 × 10²) | Surface Mount Device marking | ||
| SMD Equivalent (4-digit) | 6801 (680 × 10¹) | Precision SMD marking | ||
Decoding the Bands and Common Misreads
Resistor color coding follows a strict left-to-right reading order. The tolerance band (Gold, Silver, or Brown) is typically separated by a slightly larger gap from the value bands and is positioned on the right. If there is no gap, hold the resistor so the Gold or Silver band is on the far right.
Why 5-Band 6.8k Resistors Exist (The E-Series Nuance)
You might wonder why a 5-band resistor would be used for 6.8 kΩ, since 6.8 is a standard E24 (5% tolerance) value, and 5-band coding is usually reserved for E96 (1% tolerance) values that require three significant digits. While rare, some manufacturers produce 5-band E24 resistors for automated insertion machines that require uniform physical dimensions. In this case, the third digit band is simply Black (0), making the significant digits 6-8-0, followed by a Brown (×10) multiplier. This yields 680 × 10 = 6800 Ω. Always verify the tolerance band to confirm whether you are holding a 4-band or 5-band variant.
Rows People Get Wrong: The Faded Band Trap
When sorting through mixed grab-bags under harsh fluorescent or warm LED bench lighting, specific color bands become visually indistinguishable. Here are the most common misreads for the 6.8 kΩ value and how to catch them:
- Grey (8) vs. Violet (7): Under yellowed lighting, violet bands can look brown, and grey can look washed-out blue. If you misread Grey as Violet, you will calculate 6.7 kΩ. While close, this 1.5% error can throw off a precision op-amp gain stage.
- Red Multiplier (×100) vs. Orange (×1000): This is the most critical misread. A faded Red band looks exactly like Orange. If you read the multiplier as Orange, you will assume the resistor is 68 kΩ instead of 6.8 kΩ—a 10x error that will completely alter a bias network or filter cutoff frequency.
- Gold Tolerance vs. Brass/Yellow: Some cheap carbon film resistors use a very pale gold that looks almost yellow. True yellow is not a standard tolerance color. If it looks yellowish, assume it is Gold (±5%).
Regional Standards, Faded Markings, and Verification
A common point of confusion for hobbyists crossing over from home wiring to electronics is the assumption that the National Electrical Code (NEC / NFPA 70) governs component colors. It does not. The NEC strictly dictates wire insulation colors for mains and branch circuits (e.g., green/bare for ground, white for neutral). Component markings are governed entirely by international electronics standards.
IEC 60062 vs. Legacy Regional Standards
Globally, resistor color codes are standardized under IEC 60062. This standard defines the exact RGB values for the band paints and the alphanumeric coding systems. In the US, this harmonized with the legacy EIA-RS-279 standard decades ago. However, if you are repairing vintage equipment or reading old UK schematics, you will encounter the BS 1852 standard. BS 1852 rarely used color bands; instead, it used an alphanumeric 'R notation' printed directly on the component body. For a 6.8 kΩ resistor, a vintage UK schematic or component body will be marked as 6K8. The 'K' replaces the decimal point to prevent misreading if the print is smudged (e.g., 6.8K could be misread as 68K if the dot rubbed off, but 6K8 is unambiguous).
Safe Interpretation When Markings are Faded or Missing
Carbon composition resistors (common in pre-1980s audio gear) are notorious for their paint flaking off or the body darkening due to heat stress, rendering the color bands invisible. Metal film resistors (typically housed in a blue cylindrical body) hold their color better but can still scorch.
When visual identification fails, follow this verification protocol:
- Isolate the Component: Remove the resistor from the circuit entirely.
- Zero Your DMM: Touch your multimeter probes together. If your meter has a 'Relative' (REL) or 'Zero' button, press it to null out the lead resistance (typically 0.1 to 0.3 ohms). This is crucial for low-value resistors, though less critical for a 6.8 kΩ part.
- Measure and Correlate: Set your DMM to the 20kΩ range.
- If the reading settles between 6.46 kΩ and 7.14 kΩ, you have a standard 5% (Gold tolerance) 6.8 kΩ resistor.
- If the reading is tightly clustered between 6.73 kΩ and 6.87 kΩ, it is a 1% (Brown tolerance) precision resistor.
- If the meter reads ~68 kΩ, you misread the Red multiplier band as Orange.
- Check the Body Color: If the bands are completely gone but the body is intact, note the base material. A brown/tan body indicates carbon film (usually 5% tolerance, E24 series). A blue body indicates metal film (usually 1% or 2% tolerance, E96 or E24 series). A green body typically indicates a wirewound or fusible resistor.
For a deeper dive into standard component values and how the E24 and E96 series are calculated, refer to All About Circuits' comprehensive resistor reference guide or EEPower's breakdown of resistor standards and codes. Always trust your multimeter over your eyes when dealing with faded components on a critical PCB repair.
