ACF File

What are ACF files and how to open them

Are you having problems opening an ACF file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your ACF files.

What is an ACF file?

ACF files have multiple uses, and ASCII Color Format is one of them. Read more about the other uses further down the page.

ASCII Color Format

ACF files contain the unique ASCII color codes for the different colors you can use in your coding or website. Each color has its unique ACF code; for example, /u001b[31m will give you the color red. You can find these format codes by typing "ASCII color codes" into your browser.

How to open ACF files

Important: Different programs may use files with the ACF file extension for different purposes, so unless you are sure which format your ACF file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested nine different ACF openers which you will find listed below.

Last updated: August 16, 2026

All known file formats using extension .ACF

While ASCII Color Format is a popular type of ACF-file, we know of 5 different uses of the .ACF file extension. Different software may use files with the same extension for different types of data.

DB/TextWorks Database Access Control

These ACF files are DB/TextWorks Database Access Control files, files that control access to a database. DB/TextWorks is a combination of database and text retrieval software. You use the DB/TextWorks database type to store and manage information like multimedia, bibliographic, documents, etc. You can build your database once and publish it anywhere. You can manage it with ease, and it has a fast and precise searching capability. DB supports file formats such as ASCII-delimited files and text from Microsoft Office or PDFs, so transferring existing records is easy to do. Drag-and-Drop form design, easy table creation, Image management, and website publishing are some of the features you have access to.

DreamLight PixelPalette Colors Data

DreamLight PixelPalette Colors Data files (extension .ACF) store predefined color palettes created by DreamLight Incorporated for use in graphics and multimedia design work. These files are part of the DreamLight PixelPalettes toolkit, designed to help artists and web designers define and organize sets of colors visually rather than leaving them in arbitrary order. Such files are used to provide lookup tables or organized color tables for programs like Adobe Photoshop, Macromedia FreeHand, Director, or any graphics editor that can import custom palettes so that users can pick colors more intuitively.

An .ACF file is generated by the DreamLight PixelPalettes software and contains metadata in addition to the actual palette entries. The metadata includes fields such as library version (LIBRARYVERSION), preferred color model (PREFERREDMODEL), a message or notes section (ABOUTMESSAGE), copyright strings, prefix/suffix settings (PREFIX, SUFFIX), column and row counts (COLUMNS, ROWS), number of entries (ENTRIES), names for the colors (NAMES), and charting modes/models (MODELS). The actual colors are stored in a DATA section. Typically these files ship in the commercial PixelPalettes package and are used by purchasing or licensing the product, then opening the .ACF in graphics software to extract or apply the color values.

In technical signature, the file begins at offset zero with the ASCII string "ACF1.0.DreamLight" (hex bytes 41 43 46 20 31 2E 30 0D 44 72 65 61 6D 4C 69 67 68 74 A8 20), and inside the file you will find a variety of identifier keywords such as "THIS PIXELPALETTE IS PART OF THE DREAMLIGHT …", "PIXELPALETTE SHAREWARE COLLECTION.", "DREAMLIGHT INCORPORATED.", and field names including LIBRARYVERSION, PREFERREDMODEL, ABOUTMESSAGE, COPYRIGHT, COLUMNS, ENTRIES, MODELS, PREFIX, SUFFIX, NAMES, DATA, ROWS, and TYPE.

Microsoft Agent Character

Microsoft uses these ACF files to distribute their Microsoft Agents over the internet. Microsoft Agents combine animated characters, text-to-speech engines, and speech recognition to improve the interaction between users over the internet. a Great example of an Agent would be "Clippy the Office Assistant". Microsoft provided four characters that you could use for free, known as Peedy, Merlin, Genie, and Robby. You could even create your very own characters using Microsoft's development tools. The only web platform used is Internet Explorer because other browsers are not compatible with ActiveX.

X-Plane Aircraft

X-Plane Aircraft files with the ".acf" extension are plain text files used by the flight simulator X-Plane to define every detail of an aircraft's flight model, geometry, performance, weight & balance, configurations, and metadata as authored via Plane Maker. They control how the aircraft flies, what it looks like, what sounds it uses, how its aerodynamic surfaces respond, and how it appears in the UI.

Plane Maker is the tool bundled with X-Plane that writes .acf files. Designers load or create an aircraft in Plane Maker, edit its aerodynamic, weight, object/model, texture, and metadata fields, then save to an .acf. X-Plane reads the .acf at runtime to simulate the aircraft and display it in the aircraft selection screen. From X-Plane 10 onward, the format is human-readable text, allowing manual editing and version control; earlier X-Plane versions (up to v9) used a binary form.

Technical signature detail: in text‐based .acf files there are readable keywords like "PROPELLER).AFL", "SYMMETRICAL).AFL", "GOOD", "NACA", and typical binary signatures have long runs of zero bytes at fixed offsets.

ACF opener for Windows

We have identified one ACF opener that is compatible with this specific type of ACF file.

Various apps that use files with this extension

These apps are known to open certain types of ACF files. Remember, different programs may use ACF files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about ACF file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.