What Is an ACB File?

Some ACB files are Color Book files, but others are archives or audio files

By
Tim Fisher
Photo of Tim Fisher, Lifewire GM and Writer
Tim Fisher
Senior Vice President & Group General Manager, Tech & Sustainability
  • Emporia State University

Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the SVP and General Manager of Lifewire.

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Updated on February 9, 2023

What to Know

  • Photoshop and AutoCAD use Color Book files that end in the ACB file extension.
  • ACB2XML can convert a Photoshop ACB file into XML.
  • Other ACB files could be archives or audio packages.

This article explains the handful of file formats that use the ACB file extension, plus how to open each type.

What Is an ACB File?

A file with the ACB file extension is an Adobe Photoshop Color Book file. It provides an easy way to comply with particular color standards, like for if you're printing an image versus using it for on-screen purposes.

AutoCAD Color Book files use the ACB extension, too. Files of this type store collections of colors that the AutoCAD software can use to fill in surfaces and lines. They're useful for creating a template of colors that a company can use across all of their designs.

ACB is also the extension used for an archive file format utilized by AOL for software installations; ACB, in this case, stands for AOL Cab Launcher. Another use is as an audio package for some video games.

acb files for photoshop
Photoshop ACB files.

ACB is also short for a number of terms that have nothing to do with these file formats, like adapter control block, automatic callback, and automatic color balance.

How to Open an ACB File

Photoshop ACB files are used with Adobe Photoshop, as well as InDesign and Illustrator. Photoshop stores several ACB files in its default installation directory under the folder \Presets\Color Books\.

Some of the color catalogs included with Photoshop are FOCOLTONE, HKS, TRUMATCH, TOYO, and PANTONE. To use an ACB file with Photoshop, open the program's Color Picker tool (from either the foreground or the background color swatch on the Tools panel; the tool with the two overlapping colors). Select Color Libraries and then choose the file from the Book drop-down menu.

Photoshop color libraries

Autodesk AutoCAD opens Color Book files used by that program. You can create your own with the AutoCAD Color Book Editor. To use them, place ACB files in the \Support\Color\ folder of AutoCAD's installation directory. These ACB files are stored in the XML format, so you can use any text editor to see the RGB values for each color.

As for AOL Cab Launcher files, it's likely that it's just an archive format, like ZIP or RAR, that AOL software use during a program's installation phase. If you think your file is used for this purpose, you can try to open it with a file extraction utility like 7-Zip.

ACB audio packages contain ADX- or ADX2-formatted audio for game-related sounds, like music, dialogue, etc. You might have luck opening the file with VGMToolbox.

Considering that there are several relatively common formats that use the ACB extension, you may find that the program that Windows is configured to open when you double-click or double-tap on these types of files isn't the one you'd like. If this is the case, it's possible to change the file associations in Windows to edit which program launches when you try to use the file.

How to Convert an ACB File

The free command-line tool ACB2XML for Windows can generate an XML file from a Photoshop Color Book file so that you can see each color book's lightness and chrominance values.

To do this, once you've downloaded and extracted ACB2XML to its own folder, execute this command in this manner from the same folder: 

acb2xml.exe file.acb > file.xml

Be sure to swap out the file.acb file name with the right name for your ACB file. You can name the XML file whatever you like.

Still Can't Open the File?

Some file extensions look awfully similar, so it's understandably easy to misread them. When this happens, you end up trying to open a file in a program that doesn't support that format. This usually results in errors and other confusing messages.

For example, an ABC file appears to be related to ACB, but it's really not. There are a few file formats an ABC file could be in, and none of them are related to the formats described above. ACCDB is another example.

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