Color Difference Calculator

What Is the Color Difference Calculator?

The color difference calculator compares Hex Color A and Hex Color B using RGB distance — the straight-line (Euclidean) distance between the two colors' red, green, and blue channel values, treated as a point in three-dimensional RGB space. Click Calculate and the Difference field reports both the raw distance and a percentage showing how different the two colors are relative to the maximum possible distance between any two colors (pure black versus pure white).

This is a genuinely useful, fast way to answer "how close are these two colors?" — but it's worth being precise about what it measures. RGB distance treats the red, green, and blue channels as three equally-weighted numeric axes. It does not attempt to model how the human eye actually perceives color, the way the CIE's Delta-E (ΔE) family of formulas does. If you need a perceptually-calibrated color-difference standard for print or brand-matching QA, RGB distance is a reasonable, fast approximation — not a substitute for a true Delta-E measurement.

How RGB Distance Is Calculated

The calculator treats each hex color as a point (R, G, B) with each channel ranging from 0 to 255, and computes the ordinary Euclidean distance between the two points: Since it isn't capped at 32-bit or 64-bit ranges, the hex to decimal converter stays accurate even on unusually large hexadecimal inputs. The fastest way to read EBCDIC-encoded hex bytes as plain text is to paste them into the ebcdic to text converter.

$$ \text{distance} = \sqrt{(R_2-R_1)^2 + (G_2-G_1)^2 + (B_2-B_1)^2} $$

The percentage shown alongside it expresses that distance as a share of the largest distance any two colors can have — from #000000 (black) to #FFFFFF (white), a distance of √(3 × 255²) ≈ 441.7:

$$ \text{percent different} = \frac{\text{distance}}{441.7} \times 100 $$

Worked Example: #FF5733 vs #FF6A4D

Two warm reds — #FF5733 (R:255 G:87 B:51) and #FF6A4D (R:255 G:106 B:77) — look close at a glance. Running the RGB distance formula:

$$ \sqrt{(255-255)^2 + (106-87)^2 + (77-51)^2} = \sqrt{0 + 361 + 676} = \sqrt{1037} \approx 32.2 $$

That's a distance of about 32.2 out of a maximum of 441.7 — roughly 7% different. Small in absolute terms, but large enough that most people would notice the two side by side, since the shift is concentrated in the green and blue channels rather than spread thin across all three.

Worked Example: #1A1A1A vs #1B1B1B

Two near-blacks that differ by exactly one unit in every channel — #1A1A1A (26,26,26) and #1B1B1B (27,27,27):

$$ \sqrt{(1)^2 + (1)^2 + (1)^2} = \sqrt{3} \approx 1.7 $$

A distance of 1.7 out of 441.7 is under half a percent different — for all practical purposes, the calculator confirms these two hex codes are indistinguishable, which is exactly the kind of single-step drift check this tool is useful for during a design-token audit.

Common Uses for a Hex Color Difference Calculator

Design-System QA

Design tokens drift over time as they get copy-pasted, re-exported, or manually tweaked across a codebase. Running a suspicious pair of hex values — say, a button color from the design file versus the one actually shipping in CSS — through this calculator quickly confirms whether they're truly identical, a rounding artifact, or a real, intentional change.

Checking a Color Extraction or Handoff

When a color moves between a design tool and production CSS, small conversions (RGB rounding, color-profile differences) can introduce drift. Comparing the original hex value to the one that actually shipped tells you whether that handoff introduced a meaningful discrepancy or just noise.

Spotting Near-Duplicate Colors in a Palette

If you're auditing a color palette or a CSS variable list for near-duplicate entries that should probably be consolidated into one token, running pairs through the calculator is a quick way to flag which ones are close enough to merge.