ICC Color Profiles: The Metadata You Probably Want to Keep

An ICC color profile is a small block of data embedded in an image that tells software what its RGB numbers actually mean, so the same colors appear on different screens and printers. Unlike GPS coordinates or camera serial numbers, a standard ICC profile reveals essentially nothing about you, and removing it can make colors look dull or shifted. That is why it is the one piece of metadata most cleaners, including ours, deliberately keep.

This article explains what is inside a profile, how Display P3 differs from sRGB, exactly why colors change when a profile disappears, and the narrow cases where a profile could say something about you.

What an ICC color profile actually is

A pixel stored as red 255, green 0, blue 0 does not describe a color on its own. It means "as red as this color space's red goes", and different color spaces have different reds. A profile defines the color space, so software can turn those numbers into absolute, measurable colors.

The format is standardized by the International Color Consortium (ICC) in the ICC.1 specification, also published as ISO 15076-1. A profile maps the device's values into a device-independent reference space, the Profile Connection Space, which is based on CIE XYZ or CIE Lab. Color-managed software then maps from that reference into your display's own profile. The two-step design is what lets a photo from any camera look consistent on any calibrated screen.

For the RGB images you share, the profile is usually small and contains a few key ingredients:

• A header of 128 bytes with the profile version, the color space, the profile class (display, input, output), a creation date and time, and signature fields for the manufacturer, model and creator.
• Primaries (rXYZ, gXYZ, bXYZ): exactly where pure red, green and blue sit.
• A white point (wtpt, together with chromatic adaptation data).
• Tone curves (rTRC, gTRC, bTRC): how values map to brightness.
• Text tags: a description (desc), such as "Display P3" or "sRGB IEC61966-2.1", and a copyright notice (cprt).

sRGB vs Display P3 vs Adobe RGB

Three RGB color spaces cover most images you will encounter. They differ mainly in where their red and green primaries sit, which defines how saturated a color they can describe (their gamut).

Display P3 keeps sRGB's white point and tone curve but pushes red and green further out, so it can describe more vivid reds, oranges and greens. Adobe RGB extends mostly into greens and cyans. All three share the same blue primary.

Apple's iPhones have captured photos in Display P3 since the iPhone 7, so the majority of iPhone photos are wide-gamut images that rely on their embedded profile.

Why removing an ICC profile shifts colors

When an image has no profile, software has to guess, and the standard guess is sRGB. CSS Color Level 4 treats untagged images as sRGB, and the WebP container specification says sRGB should be assumed when no ICC chunk is present.

Now consider a Display P3 photo of a red car. The paint is stored near P3's maximum red. Strip the profile and the same numbers are read as sRGB's maximum red, which is a less saturated red. Nothing in the file's pixel data changed, but the interpretation did:

• Display P3 image without its profile: saturated reds, oranges and greens look flatter. Skin tones and sunsets lose some warmth. On images with mostly muted colors, the difference can be hard to see.
• Adobe RGB image without its profile: the whole image tends to look dull and slightly washed out, with greens and cyans affected most.
• sRGB image without its profile: usually no visible change, because the guess happens to be right.
• CMYK JPEG without its profile: colors can be badly wrong, because there is no universal default for CMYK inks.

The opposite mistake also happens: if an editor assigns the wrong profile to an image instead of converting, colors become oversaturated or shifted. The rule is simple. A profile can be removed safely only after the pixels have been converted to sRGB.

Where the profile is stored in JPEG, PNG, WebP and HEIC

The profile is separate from EXIF, XMP and IPTC in every one of these formats. That separation is what makes it possible to remove all the descriptive metadata while leaving the profile in place, without touching the pixels.

Does an ICC profile contain personal information?

For the profiles found in almost all shared photos, no. An iPhone's Display P3 profile, the common sRGB profile or the Adobe RGB profile a camera embeds is the same block of bytes across huge numbers of images from countless people. Its description says "Display P3", not anything about you.

The header does contain a creation date and fields for device manufacturer and model, which sounds concerning. In standard profiles, those values describe when and by whom the profile itself was made, which is years before your photo and the same for everyone.

There is one narrower case worth knowing about: custom calibration profiles. If you calibrate a monitor or printer, the software creates a profile specific to your hardware. Its description may contain a name you or the software chose, and its creation date is your calibration session. Images exported with such a profile embedded, which usually happens by mistake, carry a fingerprint that could link them to one workstation. The fix is not to strip the profile blindly but to convert to a standard space such as sRGB when you export.

How to see which profile an image has

With ExifTool, this shows the profile's name and header details:

exiftool -icc_profile:all photo.jpg

Look at ProfileDescription, ProfileDateTime and DeviceModel. To save the profile to a separate file for inspection, the ExifTool documentation gives this command:

exiftool -icc_profile -b -w icc photo.jpg

On a Mac, Preview shows the profile name in Tools > Show Inspector, and ColorSync Utility can open any profile. In Photoshop, the profile name appears in the document's status bar or under Edit > Assign Profile. Labels may differ slightly between versions.

How metadata tools treat the profile

Tools differ a lot here, and the difference explains many "my colors changed after cleaning" complaints:

• ExifTool: -all= deletes everything, including the ICC profile. To keep it, copy it back in the same command: exiftool -all= -tagsfromfile @ -icc_profile photo.jpg. The ExifTool cheat sheet has variations.
• ImageMagick: -strip removes profiles together with comments and metadata, and saving to JPEG re-encodes the image.
• GIMP and Photoshop: export dialogs have a separate option to save or embed the color profile, and Photoshop can convert to sRGB on export.
• Google's cwebp: copies no metadata by default, not even the profile, unless you pass -metadata icc.
• Our tool: our free metadata remover, in its default "Keep same format" mode, removes EXIF, XMP, IPTC, comments, text chunks and C2PA data but keeps the ICC profile and the orientation flag, without re-encoding the pixels.

Keeping the profile is one half of a clean, lossless result. The other half is orientation, which has the same "small technical tag, big visible effect" property; see why photos turn sideways after removing metadata. For the broader question of what lossless cleaning does and does not change, read removing metadata without losing quality.

What to do in practice

1. When you clean photos for privacy, use a method that keeps the ICC profile.
2. If a tool you rely on strips the profile, convert the image to sRGB first, then strip.
3. For images going to unknown or older software, exporting as sRGB gives the most predictable colors.
4. Check the profile description before sharing. Standard names are fine; custom names or dates suggest a calibration profile that should be replaced by sRGB.
5. If colors look duller after cleaning, compare the profile of the original and the cleaned file. A missing profile is the most likely cause.