Food and drink colour scales

Brewers, winemakers, honey and syrup packers, coffee roasters and spice traders grade colour with instruments rather than by eye, each on its own scale. These are the published scales and methods, with converters and lookups where the source defines the maths.

Beer colour: SRM and EBC

Colour value

Unit

10.0 SRM = 19.7 EBC — Deep gold to amber: The upper half of the pale ale range.

Inside the published colour range of: American Pale Ale (5–10 SRM); California Common (9–14 SRM); American Amber Ale (10–17 SRM).

From a lab measurement

Absorbance at 430 nm (1 cm cell)Dilution factor

Honey colour: USDA designations

Pfund reading (mm)

Extra Light Amber (over 34 and up to 50 mm)

The standard states that colour is not a factor of quality for US honey grades (Grade A, B, C are scored on other factors). Colour designations are a trade description. Honey also darkens with storage and heating, so a designation describes the sample when tested.

Wine colour: intensity and shade

OIV method OIV-MA-AS2-07B, defined for red and rosé wines. Enter the absorbance read at each wavelength in the cell you used. The method asks for a cell that brings each reading between 0.3 and 0.7, then refers the readings to a 1 cm path.

Absorbance at 420 nmAbsorbance at 520 nmAbsorbance at 620 nmCell path (cm)

Enter three absorbance readings to calculate.

Colour intensity and shade are conventions built from three wavelengths. They say how much light a wine absorbs and whether yellow-brown or red absorption dominates; they do not describe what the wine looks like in a glass, and two wines with the same pair of numbers can look different. The method is scoped to red and rosé wines, and no published bands attach colour names to its values.

Maple syrup colour: USDA classes

Light transmittance (%Tc)

Grade A Amber — taste descriptor: Rich (50.0–74.9%)

A higher number is a lighter syrup. Light transmitted through the syrup at 560 nm in a 10 mm square cell, expressed against analytical-grade glycerol taken as 100%. The standard also accepts any method giving equivalent results.

All four classes are Grade A: the class describes colour and the strength of maple flavour that goes with it, not quality. The standard prints the darkest class as 'below 25.0', stored here as a 24.9 upper limit at the standard's one-decimal precision. Syrup darkens after packing, so a class describes the syrup when it was graded.

Tomato ripeness: USDA colour terms

Surface changed from green (%)

Turning: A definite change to tannish-yellow, pink, red or a mixture.

Visual estimate of how much of the surface, in aggregate, shows a definite change from green towards tannish-yellow, pink or red. The standard is illustrated by an official chart of colour photographs.

These terms describe ripeness stage for mature tomatoes of red-fleshed varieties and are used alongside a grade; they are not grades, and they say nothing about flavour or safety. A lot that fits none of them may be described as Mixed Color.

SCAA roast colour tiles (Agtron Gourmet scale)

Roasted coffee is graded with a reflectance instrument against tiles numbered from light to dark; a higher number is a lighter roast. In one study, roasts sold as light, medium and dark read about 58 (light), 48 (medium), 38 (dark).

#95(Very light)
#85
#75
#65
#55
#45
#35
#25(Very dark)

There is no universally accepted industry definition of light, medium or dark roast, and different roast analysers report on different scales, so a number on one device may not match the same number on another. Tile comparisons are made on ground coffee under controlled light.

Spice colour: extractable colour methods

Paprika and saffron are graded on the colour that can be drawn out of them into a solvent, read at one wavelength. Both method texts are sold by their owners, so what follows is what open publications state about them.

Paprika and other capsicums: ASTA extractable colour

Method:: ASTA Method 20.1 (American Spice Trade Association)
What is measured:: Carotenoids, including the red xanthophylls capsanthin and capsorubin
Extracted into:: Acetone
Read at:: 460 nm in a 1 cm cell
Reported as:: ASTA colour units

The value is the absorbance of the extract scaled by a constant and divided by the sample weight in grams, with an instrument correction factor.
Published accounts print the constant as 16.4 or as 164; it depends on the extraction and dilution convention, which could not be checked against the method text.
IC colour units are 40 times the ASTA value.

One wavelength measures total extractable pigment, not the balance of red and yellow carotenoids, so two paprikas with the same ASTA value can differ in hue. The method text is sold and was not read; no calculator is offered because the constant could not be confirmed.

Sources: ASTA Analytical Methods Manual (method listing); ASTA Color and IC Color of Paprika and Oleoresin Spices; Changes in Carotenoids and Quality Parameters of Sweet Paprika (Capsicum annuum) After an Accelerated Heat Treatment.

Saffron: Colouring strength (ISO 3632)

Method:: ISO 3632-2:2010 (test methods); ISO 3632-1 (specification, current edition 2025) (International Organization for Standardization)
What is measured:: Crocins, water-soluble glycosyl esters of the carotenoid crocetin
Extracted into:: Water
Read at:: 440 nm in a 1 cm cell
Reported as:: Absorbance of a 1% extract in a 1 cm cell, on a dry-matter basis

The same extract is read in the ultraviolet for picrocrocin (bitterness) and safranal (aroma).
The 2011 specification sorted saffron into three categories, each needing all three readings and a moisture limit to be met.
As summarised in the open literature for the 2011 edition, the colouring-strength floor ran from 120 for the lowest category to 200 for the highest.

ISO standards are sold; Colourwise read neither part. The category structure and figures are those reported for the 2011 edition by an open research paper, and the 2025 edition may differ. The spectrophotometric test cannot detect every adulterant or tell synthetic colour from natural.

Sources: ISO 3632-2:2010 Spices — Saffron (Crocus sativus L.) — Part 2: Test methods; ISO 3632-1:2025 Spices — Saffron (Crocus sativus L.) — Part 1: Specification; Determination of Saffron Quality through a Multi-Analytical Approach; Distribution of Main Bioactive Compounds from Saffron Species as a Function of Infusion Temperature and Time in an Oil/Water System.

No ASTA calculator is offered. The value is an absorbance multiplied by a scaling constant and divided by the sample weight, and open sources print that constant differently depending on how the extract is diluted. Colourwise could not confirm it from the American Spice Trade Association’s own method text, so a calculator here would imply a precision it does not have. The one conversion that is stated consistently is that IC colour units are 40 times the ASTA value.

How this works

Beer: SRM is 12.7 × absorbance at 430 nm through a 1 cm cell, EBC is 25 × the same absorbance, so EBC ≈ 1.97 × SRM (BJCP colour guide). Band names are Colourwise's grouping of the BJCP 2021 style ranges, not a published scale.
Honey: designations and Pfund boundaries are transcribed from the USDA grading standard.
Coffee: tile numbers from the SCAA/Agtron roast classification; only the end labels are published names.
Wine: OIV method OIV-MA-AS2-07B (Compendium of International Methods of Wine and Must Analysis). Each absorbance is divided by the cell path to refer it to 1 cm; colour intensity is A420 + A520 + A620 and shade is A420 ÷ A520, both to three decimal places.
Maple syrup: the four Grade A colour classes and their limits are transcribed from the United States Standards for Grades of Maple Syrup (USDA, effective 2 March 2015), measured as light transmitted at 560 nm through 10 mm against glycerol at 100%. Readings are rounded to one decimal place, as the standard prints them.
Tomatoes: the six colour terms and their surface percentages are transcribed from §51.1860 of the United States Standards for Grades of Fresh Tomatoes (USDA, effective 1991).
Spices: wavelengths, solvents and units are taken from the American Spice Trade Association's method listing, an instrument maker's summary and open research papers that apply ASTA Method 20.1 and ISO 3632-2.

Limitations

No swatches are shown on purpose. How dark a beer or honey looks depends on the glass or jar, the light and the product's own absorption, and no verified conversion to screen colour exists for these scales.
Colour grades are trade descriptions. None of them measures quality or safety, and the USDA says so explicitly for honey.
A single-wavelength beer number says how dark a beer is, not its hue: two beers with the same SRM can look different.
The wine indices are defined for red and rosé wines only and carry no official colour names. They describe light absorbed by a thin layer of clarified wine, not how the wine looks in a glass.
Maple syrup classes describe colour and flavour strength, not quality: all four are Grade A. Syrup darkens after packing, so a class describes the syrup when it was graded.
Tomato colour terms are ripeness stages for red-fleshed varieties, judged by eye; they are not grades and say nothing about flavour or safety.
The ASTA manual and ISO 3632 are sold and were not read. The saffron categories described are those reported for the 2011 edition; a 2025 edition has replaced it.

Food and drink colour scales

Beer colour: SRM and EBC

Honey colour: USDA designations

Wine colour: intensity and shade

Maple syrup colour: USDA classes

Tomato ripeness: USDA colour terms

SCAA roast colour tiles (Agtron Gourmet scale)

Spice colour: extractable colour methods

Paprika and other capsicums: ASTA extractable colour

Saffron: Colouring strength (ISO 3632)

How this works

Limitations

Read next

Food and drink colour scales

Beer colour: SRM and EBC

Honey colour: USDA designations

Wine colour: intensity and shade

Maple syrup colour: USDA classes

Tomato ripeness: USDA colour terms

SCAA roast colour tiles (Agtron Gourmet scale)

Spice colour: extractable colour methods

Paprika and other capsicums: ASTA extractable colour

Saffron: Colouring strength (ISO 3632)

How this works

Limitations

Read next