Delta E Explained: How Color Difference Is Measured

Delta E color difference is a numerical measurement of the distance between two colors in the CIELAB color space. A smaller Delta E means the colors are closer, while a larger value means there is a greater difference between them. Delta E is used in printing, quality control, color matching, and tasks such as finding the nearest Pantone color to a digital reference.

What is Delta E?

Delta E, often written as ΔE, turns the difference between two measured colors into a number.

Instead of saying that two blues "look almost the same," a color workflow can measure each blue, represent them in a defined color space, and calculate their difference.

A Delta E of 1 represents a much smaller color difference than a Delta E of 10.

The calculation is especially useful when a production process needs a repeatable tolerance rather than a visual judgment alone.

What is CIELAB?

CIELAB, often shortened to Lab, represents color using three coordinates.

• L* is lightness, from 0 (black) to 100 (white)
• a* is position along a green-to-red axis
• b* is position along a blue-to-yellow axis

Because Lab is designed around perceptual color relationships rather than RGB device channels or CMYK ink percentages, it provides a useful space for comparing colors numerically. The color converter shows the Lab values of any color alongside its HEX, RGB and HSL.

Delta E calculates the distance between two positions in this space, although the exact calculation depends on which Delta E formula is used.

CIE76 Delta E

CIE76 is the simplest of the common Delta E formulas.

It treats the L*, a*, and b* values as coordinates and calculates the straight Euclidean distance between the two colors.

If two colors occupy nearby points in Lab space, their CIE76 Delta E is small. If they are far apart, the value is larger.

The limitation is that equal mathematical distances in CIELAB do not correspond to equal perceived differences across every hue and saturation region.

CIE94 Delta E

CIE94 improved on the basic CIE76 calculation by introducing weighting for different aspects of color difference.

It treats lightness, chroma, and hue differences separately rather than relying only on straight geometric distance.

This makes it better suited to practical color evaluation in applications where human perception matters, but another refinement followed.

CIEDE2000 Delta E

CIEDE2000, also written as ΔE00, further adjusts how lightness, chroma, and hue differences are weighted.

It accounts for known perceptual non-uniformities more effectively than the simple CIE76 distance, especially in the blue region and for low-chroma colors.

CIEDE2000 is the current standard formula used when perceptual color difference needs to be evaluated carefully. It is the formula behind the Pantone matching on this site.

When comparing Delta E numbers, make sure you know which formula produced them. A CIE76 result and a CIEDE2000 result for the same pair of colors are not the same number.

What Delta E values mean

Delta E does not have a universal line where colors suddenly change from "the same" to "different." Human perception varies, and viewing conditions matter.

A useful rough guide:

• Below 1: not perceptible to most people
• 1 to 2: visible on close inspection
• 2 to 10: perceptible at a glance
• Above 10: the colors read as clearly different

Treat these ranges as practical guidance rather than absolute boundaries.

The same numerical Delta E can appear more or less noticeable in different regions of color space.

Delta E in print production

Printing uses Delta E to evaluate whether a produced color is sufficiently close to an approved target.

A brand might have a measured Lab target for a corporate color. Printed samples are then measured and compared with that reference.

Typical print tolerance targets for important brand colors are around Delta E 2 to 3, although the required tolerance depends on the customer, print process, measurement conditions, substrate, and specification being followed.

A production requirement should state the actual tolerance rather than assuming one number applies to every job.

Delta E and Pantone matching

Delta E is also how the closest Pantone reference to another color is found.

Suppose you start with a HEX color. The digital value is converted through XYZ into Lab coordinates, then compared with the published Lab or sRGB simulation of every Pantone reference.

Each candidate produces a color-difference value. The Pantone reference with the smallest Delta E is the closest numerical candidate among the colors being searched.

This is the principle behind the hex to pantone and cmyk to pantone tools, which show the Delta E next to each candidate. What is Pantone covers why that match is always an approximation.

A low Delta E does not turn the HEX value into a physical Pantone ink. The match still needs physical confirmation when print accuracy matters.

A simple Delta E example

Imagine two dark blues.

The first is the approved brand blue. The second is a printed sample that appears almost identical when viewed separately.

After both colors are measured under defined conditions, the CIEDE2000 calculation produces a small Delta E, say 1.5.

That tells you the measured colors are close numerically. Whether the difference is acceptable depends on the tolerance established for that particular print job.

If another printed blue produces a Delta E of 6, it is farther from the target and will look visibly different when the two are side by side.

White point and conversion conditions matter

Delta E calculations require properly defined color data.

If your starting colors are sRGB values, they are converted through XYZ before being represented in Lab. A defined reference white is part of that conversion.

D65 is the reference white of sRGB and most screen workflows. D50 is the reference white used in ICC print workflows.

Do not compare Lab values produced under inconsistent assumptions and expect the Delta E result to provide a reliable production judgment.

Limitations of Delta E

Delta E reduces a complex visual difference to one number, which is useful but incomplete.

Two pairs of colors can have the same Delta E while appearing differently noticeable to a viewer. Differences in hue, chroma, and lightness are not perceived identically across all colors.

Viewing conditions also matter. Lighting, surrounding colors, paper, surface finish, display calibration, and observer differences influence what you see.

For that reason, numerical measurement and visual evaluation are used together in professional color workflows.

How to compare two colors

Start by making sure both colors are represented under compatible color conditions.

For digital values, use the color converter to see each color in Lab. If the goal is Pantone matching, use hex to pantone or cmyk to pantone and read the Delta E shown with each candidate.

For production comparison, measure the target and sample with a spectrophotometer and calculate Delta E using the formula specified by the production standard or customer, usually CIEDE2000.

Then compare the result with the tolerance established for that job rather than treating a generic threshold as a universal pass or fail.

FAQ

What does Delta E measure?

Delta E measures the numerical color difference between two colors represented in CIELAB. Smaller values indicate closer colors, while larger values indicate greater differences.

What is a good Delta E for printing?

Requirements vary, but important brand-color tolerances are often around Delta E 2 to 3. The correct limit depends on the print process, substrate, measurement conditions, customer specification, and Delta E formula being used.

What is the difference between CIE76 and CIEDE2000?

CIE76 calculates a simple Euclidean distance between two Lab colors. CIEDE2000 applies weighting to lightness, chroma, and hue differences to better reflect human color perception.

Can Delta E find the closest Pantone color?

Yes. Color difference is used to rank Pantone references by similarity to a target color. The hex to pantone tool does this and shows the Delta E, but important physical colors should still be confirmed with a current Pantone guide and a proof.