Colour Matcher — nearest Fersan dye from HEX/RGB (ΔE2000)

Give a HEX or RGB colour and it returns the closest colour from Fersan’s in-house dye library by ΔE2000, plus a closeness score.

Formula

Step 1: sRGB → CIELAB (D65 white point: Xn=0.95047 · Yn=1.0 · Zn=1.08883). Step 2: compute CIEDE2000 (ΔE2000) between the input colour’s Lab value and each library dye’s Lab value; the dye with the smallest ΔE is the nearest match. The colour difference is an estimated on-screen value — a binding match is confirmed by a physical lab-dip. IMPORTANT: Pantone TCX values are proprietary and are not embedded; only Fersan’s curated in-house palette is used.

Worked example

Input #1E5AA8 → RGB(30, 90, 168) → CIELAB(L*=38.58 · a*=10.30 · b*=-47.28). The library is ranked by ΔE2000: the nearest match is “Saraçoğlu Blue” #235FA6 → ΔE≈1.80 — close enough to be indistinguishable to the eye in most conditions.

Estimated — indicative value. · On-screen estimate · binding match via lab-dip. No Pantone TCX embedded.

Frequently asked questions

How do I find the equivalent of a HEX colour?

The HEX code is converted to RGB, then to CIELAB under the D65 white point. The ΔE2000 difference is computed against every colour in the Fersan dye library, and the dye with the lowest ΔE is returned as the closest equivalent. The result is a screen-based estimate; it is confirmed by a lab-dip before production.

What is ΔE?

ΔE is a metric that expresses the total difference between two colours as a single number. In CIELAB space the differences on the lightness (L*), red-green (a*) and yellow-blue (b*) axes are combined. The closer to zero, the more identical the colours. This tool uses ΔE2000 (CIEDE2000), which correlates best with human perception.

Which ΔE counts as a “match”?

Common guidance: ΔE ≤ 1.0 is imperceptible to the eye, ΔE 1-2 is very close, and ΔE 2-3.5 is commercially acceptable. The exact limit depends on the colour, end use and customer standard — each brand sets its own tolerance.

Will you give me a Pantone number?

No. Pantone TCX values are proprietary and are not embedded in this tool. Matching is done only against Fersan’s in-house, curated dye library. Share your Pantone reference and we will hit it at the physical lab-dip stage.