---
title: "Color table atom ('ctab')"
framework: quicktime-file-format
role: symbol
role_heading: Atom
path: quicktime-file-format/color_table_atom
---

# Color table atom ('ctab')

An atom that defines a list of preferred colors for displaying the movie on devices that support only 256 colors.

## Overview

Overview Color table atoms define a list of preferred colors for displaying the movie on devices that support only 256 colors. The list may contain up to 256 colors. These optional atoms have a type value of 'ctab'. The color table atom contains a Macintosh color table data structure. The layout of a color table atom is as follows.  |   |   |   |   |   |   |

## Topics

### Data fields

- [Size](quicktime-file-format/color_table_atom/size.md)
- [Type](quicktime-file-format/color_table_atom/type.md)
- [Color table seed](quicktime-file-format/color_table_atom/color_table_seed.md)
- [Color table flags](quicktime-file-format/color_table_atom/color_table_flags.md)
- [Color table size](quicktime-file-format/color_table_atom/color_table_size.md)
- [Color array](quicktime-file-format/color_table_atom/color_array.md)

## See Also

### Describing movies

- [Movie atom ('moov')](quicktime-file-format/movie_atom.md)
- [Movie header atom ('mvhd')](quicktime-file-format/movie_header_atom.md)
- [User data atoms](quicktime-file-format/user_data_atoms.md)
- [Interleaving movie data](quicktime-file-format/interleaving_movie_data.md)