ACO is a Photoshop colour-swatch palette. Created and opened by Adobe Photoshop. An ACO file lets artists share a chosen set of colours between Photoshop projects. An ACO swatch can store colours in RGB, CMYK, HSB, Lab or grayscale, with each channel kept as a 16-bit big-endian value. The format has two versions, the second adding a name to every swatch while keeping the first version’s data for compatibility.

How do I open a .ACO file?

Drop a .ACO file onto Analyser at https://analyser.valjdakosta.com/ and it is identified directly in your browser - no upload, no account and no software to install. Identify Adobe project files and read their metadata: InDesign (INDD), XD, Animate (FLA), and Lightroom. After Effects projects (AEP, AET), Premiere Pro and Elements (PRPROJ, PREL), Photoshop (PSD, PSB) and Illustrator (AI) now open in full viewers - see After Effects, Premiere Pro, Photoshop and Illustrator.

Can I open a .ACO file online for free?

Yes. Analyser is a free online .ACO identifier that runs entirely in your browser - your .ACO file never leaves your device, so there is nothing to upload and no software to install. It even works offline once installed.

.ACO file - what it is and how to identify it online

Analyse a .ACO file

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What is a .ACO file?

ACO is a Photoshop colour-swatch palette. Created and opened by Adobe Photoshop.

Did you know: An ACO file lets artists share a chosen set of colours between Photoshop projects.
An ACO swatch can store colours in RGB, CMYK, HSB, Lab or grayscale, with each channel kept as a 16-bit big-endian value.
The format has two versions, the second adding a name to every swatch while keeping the first version’s data for compatibility.
What Analyser reads: Identify Adobe project files and read their metadata: InDesign (INDD), XD, Animate (FLA), and Lightroom. After Effects projects (AEP, AET), Premiere Pro and Elements (PRPROJ, PREL), Photoshop (PSD, PSB) and Illustrator (AI) now open in full viewers - see After Effects, Premiere Pro, Photoshop and Illustrator.
Depth of analysis: .ACO is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
Open a .ACO file: Drag a .ACO file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.
Related formats: .INDD · .INDT · .IDML · .MOGRT · .SESX · .XD · .FLA · .SWF · .LRtemplate · .LRcat · .ACV · .ASL · .ABR · .GRD · .PAT. See all supported file types.