Roast color reference
Coffee Roast Color Chart & Agtron Roast Guide
Compare roast levels, estimate flavor direction, and use the interactive Agtron reference for faster roast communication.
Ground Coffee vs. Whole Bean
Ground coffee usually produces a more repeatable color reading because it reduces the influence of bean curvature, surface oil, chaff, and uneven external development. Whole-bean readings remain useful for visual batch checks, but they should not be compared directly with ground-coffee values.
Lighting and Sample Preparation
Ambient light changes visual judgment and camera-derived HEX values. Instrument readings should use the device's controlled illumination, a level sample bed, a consistent grind setting, and a clean measurement window. Allow hot coffee to cool before testing so temperature and condensation do not affect the workflow.
Scale and Instrument Differences
Agtron-style values are useful only when the sample form, instrument, calibration routine, and measurement method are recorded. Values from different devices or visual charts may not be interchangeable. Build internal acceptance ranges from your own roast profiles and cupping records.
LeBrew's original educational reference: the same eight anchors used by this interactive estimator. The values, roast labels, and flavor directions are the tool's editorial model, not a certified standard or measured sample dataset.
| Reference value |
Roast label |
Illustrative screen color (HEX) |
Typical flavor direction |
Measurement note |
| 95 | Light | #D7B48A | Floral, citrus, tea-like | High origin expression; compare only with the same sample method |
| 85 | Cinnamon | #CD9A63 | Fruit, honey, bright sweetness | Small preparation differences can noticeably move the reading |
| 75 | Medium | #BA814C | Stone fruit, caramel, light cocoa | Useful midpoint for profile-to-profile comparison |
| 65 | High | #A86B3D | Nuts, caramel, milk chocolate | Record whole-bean and ground values separately |
| 55 | City | #935B34 | Caramel, roasted nuts, cocoa | Default reference point used by this tool |
| 45 | Full City | #734320 | Dark chocolate, caramelized sugar | Surface oils and cooling time can affect visual comparison |
| 35 | French | #4D2915 | Smoky, dark chocolate, heavy body | Dark samples require a clean optical window and even sample bed |
| 25 | Italian | #2D1710 | Charred, carbon, intense roast | Use cupping and roast logs alongside the color result |
Important: these are educational reference points, not universal pass/fail limits. Screen color, camera white balance, origin, process, surface oil, grind size, sample temperature, and instrument scale can all change the apparent match.
- Define the comparison. Identify the roast batch, sample age, sample form, instrument, and scale. Compare whole beans with whole beans and ground coffee with ground coffee.
- Control the grind. Use the same grinder and recorded setting for ground samples. Keep the sampling and mixing routine consistent; do not selectively discard fines between batches.
- Prepare the instrument. Follow its current manual for warm-up, calibration checks, sample temperature, and cleaning. Use the specified reference and sample vessel.
- Prepare a level sample. Use a consistent fill depth and distribution method. Avoid exposed gaps and uneven heaps; follow the device's preparation instructions rather than adding an arbitrary tamping step.
- Check repeatability. Refill and level the sample for three separate readings. Keep each reading, its mean, and its minimum-to-maximum range; these are an internal workflow check, not a universal acceptance standard.
- Interpret the result in context. Compare the readings with your own accepted batches, roast logs, and cupping records. Investigate preparation or calibration drift before changing the roast profile.
Why Grind Size Changes the Comparison
Grinding exposes the bean interior and changes the particle surfaces, gaps, and packing presented to the sensor. A different grind or fines fraction can change the optical reading even when the roast batch is unchanged. Establish the grind method for your instrument, then keep it fixed. Do not apply a generic numerical correction between whole-bean and ground readings.
Why Lighting Changes Visual Color
For visual checks, use a consistent light source, neutral background, viewing position, and sample depth. A phone's exposure and white balance can change the recorded color; a screen adds its own brightness and color settings. A HEX match describes a displayed color, not a calibrated coffee measurement. For instrument work, use the illumination and sample cover specified by the manufacturer.
What the Same Color Does Not Prove
Two coffees can share a similar color reading while differing in origin, processing, roast development, and extraction behavior. Color is useful for checking batch consistency, but it cannot independently establish flavor quality or certify that two roast profiles are equivalent. Pair the number with sensory and process records.
Roast Color Scales and Standards: What Can Be Compared?
A comparison of measurement methods, not a numerical conversion table
| Method or reference | What to record | Comparison limit |
|---|
| LeBrew screen chart and HEX estimator | Selected anchor, HEX value, and sample context | Educational reference only. Screen swatches are illustrative and do not calibrate an instrument. |
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| SCA / SCAA physical roast-color tiles | Reference set, balanced white lighting, sample form, and viewing conditions | The eight reference disks run from 95 to 25. They support visual comparison; this page's HEX colors are not certified reproductions of those disks. |
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| Agtron Gourmet scale | Instrument model, Gourmet scale, calibration reference, and sample method | The M-BASIC II manual specifies this scale. Record the scale name rather than reporting an unqualified "Agtron number." |
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| Agtron Commercial scale | Instrument model, Commercial scale, calibration reference, and sample method | Commercial and Gourmet use different numerical mappings. Compare like with like or use the relevant manufacturer's documented relationship. |
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| HunterLab HCCI | Instrument setup, HCCI settings, and sample method | A coffee-specific index based on reflectance at 640 nm. It is distinct from CIELAB L* and from an unqualified Agtron reading. |
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| CIELAB / L* color measurements | Full reported coordinates, instrument geometry, illuminant settings, and sample preparation | L* and an Agtron-style number are different measurements. A numerical match does not establish equivalence. |
|---|
When changing instruments or scales, measure the same representative samples on both systems under documented conditions. Establish whether a relationship is useful over your working roast range before using it for production limits. This page does not supply an unvalidated Agtron-to-L* or device-to-device conversion formula.
As a model-specific example, Agtron's M-BASIC II manual gives a relationship that maps a Gourmet reading of 55 to approximately 42 on the Commercial scale. This does not convert a screen HEX value or CIELAB L* reading, and it does not independently establish equivalence with a RoastSee reading.
Choose a RoastSee Measurement Path
For a dedicated roast-color workflow, review the RoastSee C1 roast color analyzer and its sample-preparation instructions. For a broader analysis workflow, compare RoastSee Fusion against the measurements your team actually records. Confirm the supported scales, sample forms, calibration process, and export needs before choosing a device.
Need help matching the method to your roastery? Ask LeBrew about your roast-color measurement workflow, including whether you test whole beans or ground coffee and which reference system you currently use.
Technical References and Method Notes
LeBrew prepared this guide as a practical explanation. The three-reading check is a suggested internal routine, not an SCA certification protocol. The reference chart preserves this tool's original labels and flavor estimates; measured color alone does not establish a sensory score.
