Assigning sRGB to a wide-gamut file instead of converting it, which relabels the pixels without correcting them.
Colour
Colour profile
Also called color profile, embedded profile or image profile. Here is what it means, when it changes what you export, and what people get wrong.
ColourRuns on your deviceUpdated 10 August 2026
The short answer
A colour profile is the data attached to an image that says which colour space its numbers belong to. It is the label that lets software work out what a given RGB value should look like. Without one, most programs simply assume the file is sRGB.
Updated
The short version
Colour profile at a glance
| Quick fact | Detail |
|---|---|
| What it stores | Which colour space the file's numbers belong to |
| Typical size | A few kilobytes for a matrix profile such as sRGB |
| Default when missing | Most software assumes sRGB |
| Assign | Changes the label, shifts the colours |
| Convert | Changes the numbers, preserves the colours |
| Usual file format | ICC profile, embedded in the image |
Slide the table sideways to see every column.
What does an embedded profile actually do for a file?
It answers one question: what do these numbers mean? A photograph is just a grid of triples, and a triple such as 180, 60, 55 is a different red in sRGB than it is in Adobe RGB. The embedded profile removes the ambiguity, so colour-managed software can convert the values correctly for whatever display is in front of the viewer.
The cost is small. An sRGB or Display P3 profile is a few kilobytes because it stores little more than primaries, a white point and a curve. Printer profiles are far bigger because they carry lookup tables, but you rarely embed those in a delivery file.
Assign or convert: which one do you want?
These sound similar and do opposite things.
- Assign changes the label and leaves the pixel values untouched. The numbers stay the same, so the colours shift. Use it only when the existing label is wrong.
- Convert recalculates the pixel values so the colours stay where they were, and writes the new label. Use it for almost everything, including exporting a wide-gamut master to sRGB.
The classic mistake is assigning sRGB to an Adobe RGB file to make it web ready. That produces a duller, flatter picture, because the numbers were never adjusted. Converting produces a file that looks the same and is genuinely sRGB.
What happens to files with no profile at all?
They get guessed. Browsers and most editors treat untagged images as sRGB, which is a sensible default and completely correct if the file really is sRGB. If it came out of a camera set to Adobe RGB, or off a wide-gamut editing setup, the guess is wrong and the picture renders wrong.
Profiles also get lost along the way. Batch resizers, converters, screenshot tools and platform image pipelines can all strip metadata to shave bytes. If a run of listing photos suddenly looks off, check whether the output still carries a tag before assuming the edit was at fault.
What people get wrong about colour profile
Each one is a real failure mode, not a style preference.
Stripping all metadata to reduce file size, which removes the colour profile along with the EXIF data.
Embedding a monitor profile in an exported image, which describes your screen rather than the colour space the file should be read in.
Assuming a file is sRGB because it looks right on your own screen, when your screen may be sRGB and the file may not be.
Questions people ask
Colour profile, answered
The follow-up questions people search for once they have the definition.
Should I embed a colour profile in images I upload?
Yes for anything that is not already sRGB, and it does no harm for sRGB either. The profile adds a few kilobytes and removes the risk of a viewer guessing wrong. Some platforms re-encode uploads and drop it anyway, which is a further reason to convert to sRGB before uploading.
How can I tell which profile an image has?
Most editors show it in file info or the document title bar, and operating system file inspectors list it under the image's colour data. Command-line tools that read EXIF and ICC metadata will also print it. If nothing is listed, the file is untagged.
Does removing the colour profile make a file smaller?
By a few kilobytes, which is negligible next to the image data. It is not a saving worth the risk of the file being interpreted in the wrong space. If you need smaller files, compression settings and dimensions matter enormously more.
Is the profile the same thing as the colour tag?
Related but not identical. A full embedded profile carries the whole description of the space. A tag can be a much smaller marker, such as an EXIF field or a PNG chunk, that simply names a known space. Both tell software how to read the numbers.
Same cluster
More from the glossary
Neighbouring entries, so every term in the set is one hop from every other.
Colour gamut
A colour gamut is the range of colours a particular space, screen or printer can actually reproduce.
Compression artefact
A compression artefact is visible damage introduced by lossy encoding: blocky squares, halos around hard edges, muddy colour at boundaries, or stepped gradients.
Clipping path
A clipping path is a vector outline drawn around a subject so that everything outside the line is hidden.
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Sources
Where the facts on this page come from. Every link opens the specification, standard or documentation the claim was read at.
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