Why does the same colour have different numbers in every brand?

Each manufacturer dyes its own range and numbers it independently. There is no shared standard; a conversion chart is a list of nearest neighbours, and for some colours the nearest neighbour is not very near.

How close is close enough?

A colour difference (ΔE2000) under 2.3 is invisible side by side on screen; under 5 reads as the same colour on a garment; above 10 is a different colour. Sheen and thread weight shift the impression further, so check a physical card for anything above 5.

Can the matcher read the threads in my PES file?

Yes. PES from version 5 up, JEF, VP3, XXX and HUS carry colour information; the matcher lists every colour block with the nearest thread in each brand you select. DST carries no colours at all.

Which chart should a Brother owner use?

Brother's own 61-colour embroidery range, or the 63-colour Simthread set that mimics it. The machine displays Brother palette names regardless of what thread you load, so the file's colours are a hint, not an instruction.

Embroidery thread colour conversion: Isacord, Madeira, Sulky, Robison-Anton and Brother charts

Every thread brand publishes its own catalogue, with its own numbers and its own idea of "medium blue". A design digitised with Isacord numbers stitched with Madeira thread needs a conversion, and most conversion charts online are copied from each other with no indication of how close each pair actually is. This guide explains what is really being compared and how to make the decision quickly.

What a thread chart contains

A manufacturer's chart lists, for each thread, a catalogue number, a name, and an RGB value meant to represent the colour on screen. The RGB values are approximations made by the manufacturer or by whoever built the chart for software; they are not spectrophotometer readings. Two consequences:

Two brands' RGB values for visually identical threads can differ by a few units, purely from how each chart was made.
Some chart entries are plainly off. Madeira Polyneon 1641 "Black" is stored as a very dark grey in most charts rather than pure black; that does not mean the thread is grey.

Thirteen charts are built into the thread matcher: Isacord Polyester, Madeira Polyneon and Rayon, Sulky Rayon and Polyester, Robison-Anton Polyester, Floriani Polyester, Hemingworth, Marathon Polyester, Gütermann Creativ Dekor, Coats Sylko, Brother Embroidery and Janome. They come from the Ink/Stitch palette files, which are the same data most desktop embroidery software uses.

Measuring colour difference properly

Comparing RGB values by subtracting numbers gives poor results: our eyes are far more sensitive to some differences than others. The matcher converts both colours to CIE Lab and uses the CIEDE2000 formula, the industry standard for perceived difference. The result is a single number, ΔE:

| ΔE2000 | What it means on a garment | |---|---| | under 1 | Identical; even side by side you cannot tell | | 1 to 2.3 | Very close; only visible in direct comparison under good light | | 2.3 to 5 | Close; reads as the same colour unless the two threads meet | | 5 to 10 | Noticeable; a different shade of the same colour | | over 10 | A different colour |

Because the chart values are approximations, treat the numbers as ranking rather than measurement: the first match is the best candidate, the ΔE tells you whether to bother checking a second one against a physical card.

Converting a catalogue number

Pick the source brand, type the number as printed on the spool (Isacord uses four digits, so 0020 not 20), and pick the target brand. The three closest threads are listed with their ΔE. A few patterns you will see:

Neutrals convert well. Black, white and most greys have ΔE under 2 across every brand.
Saturated brights convert poorly. Isacord's 1902 "Poinsettia" red has no exact Madeira twin; the best candidates land around ΔE 4 to 6 and differ in warmth. For a large satin area, order both and compare on the fabric.
Variegated and metallic threads are not in the charts. They cannot be described by one RGB value.

Matching the threads in a design file

Drop a PES, JEF, VP3, XXX or HUS file on the matcher and every colour block is listed with the nearest thread from the brands you selected. This is the practical use: a design bought with Robison-Anton numbers, a drawer full of Isacord. The file viewer shows the same blocks with their stitch counts, so you can decide which colours matter (a 6,000-stitch fill) and which do not (a 90-stitch eye).

Two formats need a caveat:

DST has no colours. Only stops. Whatever colours a viewer shows for a DST are placeholders. Use the design's colour sheet.
PES versions 1 to 4 have only palette indices. The machine's 64-colour Brother palette is stored, not thread names. Version 5 and later can carry named threads, but many files are saved with the palette only. The matcher works from the palette colour in that case, which is a coarser starting point.

Appliqué and thread colour

For appliqué the thread question is narrower than for fill designs: the placement run and tack-down disappear under the fabric and satin, so they can be any colour that is easy to see while placing the fabric. Only the satin border shows. Match the satin to the fabric (invisible edge) or contrast it (outlined look); either way one thread does the whole design, and the chart mainly helps when a customer asks for a specific brand.

The tack-down is the one exception. On light fabrics a dark tack-down can shadow through a thin satin. Use a colour close to the satin, or the fabric colour, for the tack-down block.

Try it

Match a colour or a whole file

Thirteen brand charts, ΔE2000 distances, cross-brand conversion by catalogue number. Runs in the browser.

Open

Sources

Ink/Stitch thread palette files (GPL), the source of the chart RGB values.
CIE, "Colorimetry", CIEDE2000 colour-difference formula.
Brother embroidery thread colour chart and Simthread's 63-colour Brother-compatible set, for palette behaviour on Brother machines.