Embroidery Thread Conversion Chart and Color Converter
Enter a thread brand and color number and get the closest color in 16 other lines, from Isacord and Madeira to Brother and DMC floss. Every match carries a measured color-difference score, so you can see how close "closest" really is.
How the converter picks a match
Each thread color in the bundled data has a published RGB value. The converter turns that value into CIELAB, a color space built so that equal distances look roughly equally different to the human eye, and then measures the distance between your color and every color in each target line with the CIEDE2000 formula, the current CIE standard for small color differences. The lowest score wins.
| Score (CIEDE2000) | What it means for thread |
|---|---|
| 0 to 1 | Indistinguishable. Swap freely. |
| 1 to 2 | Very close, visible only side by side. |
| 2 to 3.5 | Close, visible side by side. Fine for a whole element, risky next to the original. |
| 3.5 to 5 | Noticeable difference. Check a color card. |
| Above 5 | Different color, check a real color card. |
What the score cannot tell you: the RGB values are screen approximations taken from published palettes, not spectrophotometer readings of real spools. Rayon has more sheen than polyester, so the same measured color can read lighter or brighter once stitched, and a satin column catches light differently from a fill. The palettes were also recorded by different people with different methods: some store black as pure #000000 and white as #ffffff, others store the measured dark grey or off-white of a real spool. Between two lines recorded differently, even equivalent colors score high (Isacord 0020 Black against Madeira Polyneon 1800 Black scores about 12), so for blacks, whites and very dark shades trust the color name and the card over the score. The makers' own cross-reference charts are made by eye and sometimes choose a different color from the same family. For a logo or a repeat order, a physical color card or a test stitch-out is the final check. Choosing the thread type itself is covered in the machine embroidery thread guide.
The math, step by step
- Hex to sRGB channels between 0 and 1.
- Inverse sRGB companding to linear light: c / 12.92 when c is 0.04045 or less, otherwise ((c + 0.055) / 1.055) to the power 2.4.
- Linear RGB to CIE XYZ with the standard sRGB (IEC 61966-2-1) matrix, D65 white point.
- XYZ to CIELAB with the D65 reference white X 95.047, Y 100.000, Z 108.883.
- CIEDE2000 distance with kL = kC = kH = 1, following the implementation notes of Sharma, Wu and Dalal (2005). Our implementation reproduces all 34 of their published test pairs to four decimal places.
- Each target line is sorted by that distance and the top 1 or 3 colors are shown with the band from the table above.
Everything runs in your browser. Nothing you type is sent anywhere.
Thread lines in the converter
17 lines and 4,691 colors. Numbers are the maker's own color numbers. Brother and Janome are the color numbers those machines display when they open a design, which is why a PES or JEF file can show "Brother 900" even if you never bought Brother thread.
| Brand | Line | Fiber | Colors |
|---|---|---|---|
| Isacord | 40 Polyester | Polyester | 398 |
| Madeira | Polyneon 40 | Polyester | 349 |
| Robison-Anton | Polyester | Polyester | 447 |
| Robison-Anton | Rayon | Rayon | 419 |
| Sulky | Rayon 40 wt | Rayon | 289 |
| Floriani | Polyester | Polyester | 286 |
| Brother | Embroidery (machine numbers) | Machine palette | 61 |
| Brothread | 40-color set | Polyester | 40 |
| Simthread | Polyester | Polyester | 107 |
| Fil-Tec | Glide | Polyester | 212 |
| Hemingworth | Polyester | Polyester | 294 |
| Gunold | Poly 40 | Polyester | 300 |
| Marathon | Polyester | Polyester | 301 |
| Mettler | Poly Sheen | Polyester | 351 |
| Coats | Sylko (USA) | Polyester | 303 |
| Janome | Embroidery (machine numbers) | Machine palette | 78 |
| DMC | Stranded cotton floss | Cotton | 456 |
Brand availability differs by country. Robison-Anton and Floriani are easiest to find in the US, Madeira and Gunold are widely stocked in Europe, and DMC is stranded cotton floss for hand embroidery, included so a hand pattern can be moved to machine thread.
Data source
The color data comes from the thread palettes of Ink/Stitch, the free embroidery digitizing extension for Inkscape, published under the GPL-3.0 license. We used the palette files at commit d59c9ab1e3 (2026-09-17), retrieved 2026-10-06, and checked every line for unreadable rows, impossible RGB values, repeated color numbers and line sizes far from what the maker sells. Exact duplicate rows were merged and two placeholder DMC rows removed.
Left out on purpose:
- Madeira Rayon: Ink/Stitch issue #3257 (open since 2024-10-28): about 350 entries for a line of roughly 180 colors, with names that do not match the numbers.
- Sulky Polyester: 907 entries with repeated numbers (1001 and 304 each name two different colors); far larger than any single Sulky polyester line, so the numbers cannot be trusted as one line.
Spot a wrong color or number? Tell us through the About page and we will check it against the maker's card.
Frequently asked questions
How do I convert an embroidery thread color to another brand?
Pick the brand you have, type its color number (leading zeros are optional, so 15 finds 0015) and choose the brands you want to convert to. The converter returns the closest color in each brand with its number, name and a CIEDE2000 color-difference score. A score of 2 or less means most people will only see the difference with the two threads side by side.
Is a converted thread color an exact match?
Rarely. Each brand dyes its own palette, so the best match in another line is usually close rather than identical. The score tells you how close: up to 1 is indistinguishable, 1 to 2 is very close, 2 to 3.5 is visible side by side, 3.5 to 5 is a noticeable difference and above 5 is a different color. The colors here are screen values from published palettes, so check a physical color card before an order where the shade matters.
Why does this converter disagree with a brand conversion chart?
Thread makers build their charts by eye or from their own measurements of real spools, and they sometimes pick a color in the same family rather than the nearest one. This tool ranks every color in the target line by measured difference from published RGB values. When the two disagree, compare both candidates on a color card or a test stitch-out.
Can I convert a whole design color sheet at once?
Yes. Choose Convert a list, pick the source brand and paste up to 30 color numbers separated by commas, spaces or new lines. You get a table with the best match in each chosen brand and a button that copies it as plain text for your notes or a shopping list.
How do I match a logo or fabric color to embroidery thread?
Choose Pick or paste a color and enter the hex code (for example #9d174d from a brand guide) or use the color picker. The converter finds the nearest thread in every brand. Screen colors and printed or woven colors differ, so treat the result as a shortlist and confirm it against a real thread card in daylight.
Does a DST file tell me which thread colors to use?
No. DST stores stitches and color changes but no thread colors or names, so a DST design opens in placeholder colors. You need the color sheet that came with the design, then this converter to move those colors into the thread brand you own.
Related guides
- Machine embroidery thread: polyester vs rayon, weights and brands
- Embroidery stabilizer guide: cut-away, tear-away or wash-away
- Embroidery file formats: PES, DST, JEF, EXP and VP3