Short answer
Either the export really changed the colour numbers — by converting to CMYK or sRGB, or by turning spot colours into process — or it left the numbers alone and dropped the profile that says what they mean, or nothing changed and the viewer is showing the file differently. Reopening the export in the application that made it tells the first two from the third; exporting once with no conversion and the profile embedded tells the first from the second.
1. The export converted the colours to another colour space
Test: Open the export dialogue and find the output or colour-conversion setting. Export one copy with no conversion and one with the preset, and compare them in the same viewer.
Print presets can convert everything to a CMYK profile, and web presets convert to sRGB. Either moves vivid colours into a smaller range.
2. The colour profile was not embedded
Test: Export again with the 'embed colour profile' option ticked and open both files side by side in the same viewer. If the tagged copy looks right, the first export left the profile out.
Without a profile the numbers have no stated meaning, and most software assumes sRGB. A wide-gamut file read that way loses saturation.
3. The viewer is not managing colour the way the application did
Test: Open the same exported file in two programs, for example a web browser and the application that made it. If they disagree, the file is intact and one viewer is at fault.
Viewers differ in whether they honour embedded profiles and in how they turn CMYK into screen colour, so one file can look right in one and wrong in another.
4. Spot colours were converted to process inks
Test: Check the ink or separations list of the exported PDF. If a named spot colour from the design is missing, it was replaced with a four-colour mix.
An export option or an ink setting can turn every spot colour into its nearest CMYK equivalent, which is usually duller.
5. JPEG compression has smeared saturated detail
Test: Zoom in on small coloured text or a sharp red edge in the export, then export the same thing as PNG or at maximum JPEG quality and compare.
JPEG usually stores colour at lower resolution than brightness, so fine saturated detail goes soft and greyish while large areas stay the same.
Causes are ordered by how often Colourwise expects each to be the explanation — an editorial judgement, so test them all.
An exported file passes through two things that the working document did not: the export settings and a different viewer. Separate them. Open the exported file in the application that produced it, beside the original. If the two match there, the export is sound and the program you first judged it in — a browser, a mail client, a system preview — is displaying it differently. If they do not match, the export altered something, and the next test is a second export with colour conversion switched off and the profile embedded. A copy that now matches means the first export was converting or stripping. This is a different problem from one file looking different on two screens, which is about the displays; here the screen has not changed, only the file or the viewer.
RGB numbers describe a colour only together with a profile that says which red, green and blue they refer to. Export options that strip metadata or leave the profile out, usually to save a few kilobytes, produce a file whose numbers are intact and whose meaning is missing. Software then assumes sRGB. For a file that was sRGB all along nothing changes. For a wide-gamut file every saturated colour is read as its weaker sRGB namesake. The table on this page puts numbers on it: full red in Display P3 loses about a fifth of its chroma when read as sRGB, a visible 7 CIEDE2000 units; full green in Adobe RGB loses more than a quarter, nearly 10 units. Blues barely move, because all three spaces share a blue primary, which is why the damage shows in reds, oranges, greens and skin.
Many export presets convert colour as part of their job. A print preset may turn everything into CMYK for one particular printing condition; a web preset turns everything into sRGB. Both move colours the destination cannot hold to the nearest ones it can, and the vivid ones move most. That is the practical meaning of 'RGB is not CMYK': there is no CMYK value that is simply equal to an RGB colour, only the nearest colour a given press and paper can print, and it differs from one printing condition to the next. Conversion is not a fault when it is chosen. It is a fault when the preset's destination is not where the file is going — a coated-paper profile for an uncoated job, or a print preset used for a file bound for a screen. Spot colours have the same trap: an option that converts them to process replaces each with a duller four-colour mix.
Two things imitate a colour change without being one. JPEG compression stores colour at a lower resolution than brightness, so small saturated details — red type, thin coloured lines, the edge of a logo — turn soft and slightly grey while large areas keep their colour; exporting at higher quality, or as PNG for graphics, cures it. And quick previews are often not colour-managed: file-browser thumbnails, mail attachments and some PDF viewers show CMYK files with a rough conversion of their own that makes them look garish or flat. Neither is in the file's colour data. Judge an export in software known to honour profiles, and for print, by the printer's preflight or a proof, not by a thumbnail.
| RGB numbers in the file | Chroma if read as sRGB | Chroma intended (Display P3) | Error if P3 is read as sRGB (ΔE00) | Chroma intended (Adobe RGB) | Error if Adobe RGB is read as sRGB (ΔE00) |
|---|---|---|---|---|---|
| Pure red (255, 0, 0) | 106.8 | 136.8 | 7.1 | 119.5 | 7.8 |
| Pure green (0, 255, 0) | 113.3 | 148.1 | 5.2 | 155.8 | 9.8 |
| Pure blue (0, 0, 255) | 131.2 | 135.4 | 1.3 | 133.1 | 0.6 |
| Orange (255, 128, 0) | 87.6 | 117.8 | 6 | 102 | 5.2 |
| Leaf green (77, 153, 51) | 58.9 | 72.4 | 3.7 | 76 | 6.7 |
| Sky blue (102, 179, 242) | 40.8 | 45.9 | 3.3 | 48.5 | 6 |
| Tan (199, 135, 66) | 50.8 | 61.5 | 3.2 | 60.8 | 4.5 |
Why: They were saved in a wide-gamut space without the profile, so browsers read them as sRGB.
Fix: Convert to sRGB on export and embed the profile, or keep the wide space and embed its profile.
Why: The export preset converted to a CMYK profile, and the orange was outside that printing condition's range.
Fix: Soft-proof with that profile before export and choose a printable orange, or ask whether a spot colour is possible.
Why: The colour channels were stored at reduced resolution.
Fix: Export graphics and text as PNG, or as JPEG at the highest quality setting.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
Colourwise analysisStrong evidence
Computed from the published definitions of the colour spaces, full red in Display P3 has a CIELAB chroma of about 137 but about 107 when the same numbers are read as sRGB, a difference of about 7 CIEDE2000 units; full green in Adobe RGB (1998) falls from about 156 to about 113, nearly 10 units; full blue changes by about 1 unit in either case.
Based on: The same 8-bit RGB triple decoded with each space's primaries, white point and transfer function, converted to CIELAB (D50, Bradford), and compared with CIEDE2000 using Colourwise's colour library; see the table.
Source: ICC colour encoding registry: Display P3; Adobe RGB (1998) color image encoding; International Electrotechnical Commission (IEC) webstore and catalogue
FactModerate evidence
Images without an embedded profile are treated as sRGB: a browser engine documents this for untagged images, and a professional photo lab states that it assumes sRGB for any file without an embedded profile and that this results in unexpected colour.
Caveat: Two documented examples of a widespread default; individual applications can differ.
Source: Improving Color on the Web (WebKit blog, 1 July 2016); Color Management FAQs
FactStrong evidence
More than one ICC profile can be built from a single characterisation data set, and separate profiles exist for different papers and ink limits, so one RGB colour converts to different CMYK values depending on the destination chosen at export.
Source: CMYK Characterization Data (registry); ECI offset profiles (colour standards: offset)
StandardStrong evidence
JPEG files in the JFIF format store colour as one brightness channel and two colour-difference channels, which is what allows the colour channels to be kept at lower resolution.
Source: JPEG File Interchange Format, version 1.02 (E. Hamilton, C-Cube Microsystems, 1992)
Reviewed 1 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.