color

Display ANSI colors in terminal

$ for i in {0..255}; do printf "\e[38;5;${i}m%3d " $i; done

$ echo -e "\e[31mRed text\e[0m"

$ echo -e "\e[44mBlue background\e[0m"

$ echo -e "\e[1mBold text\e[0m"

$ echo -e "\e[1;31;44mBold red on blue\e[0m"

$ echo -e "\e[0m"

echo -e "\e[codemtext\e[0m"
printf "\033[codemtext\033[0m"

Terminal color is controlled through ANSI escape sequences, special character codes interpreted by terminal emulators to change text appearance. These sequences start with ESC (\\e, \\033, or \\x1b) followed by formatting codes.
Colors enhance readability of command output, differentiate log levels, highlight errors, and improve user interfaces in terminal applications. Most modern terminals support 256 colors and true color (16 million colors).
The tput command provides a portable way to generate escape sequences. Environment variables like TERM and NO_COLOR influence color support detection.

Text Styles:
0 - Reset all
1 - Bold
2 - Dim
3 - Italic
4 - Underline
5 - Blink
7 - Reverse
9 - Strikethrough
Foreground Colors (30-37):
30 Black, 31 Red, 32 Green, 33 Yellow
34 Blue, 35 Magenta, 36 Cyan, 37 White
Background Colors (40-47):
40 Black, 41 Red, 42 Green, 43 Yellow
44 Blue, 45 Magenta, 46 Cyan, 47 White
256 Colors:
38;5;N - Foreground color N (0-255)
48;5;N - Background color N (0-255)
True Color (24-bit):
38;2;R;G;B - Foreground RGB
48;2;R;G;B - Background RGB

tput setaf N: Set foreground color
tput setab N: Set background color
tput bold: Bold mode
tput sgr0: Reset attributes

Not all terminals support all features; 256-color and true color require modern terminals. The NO_COLOR environment variable convention requests programs disable color output. Piping colored output to files or other programs may include escape sequences. Test terminal support with tput colors.

ANSI escape sequences were standardized in ECMA-48 in 1976, based on earlier work by ANSI (American National Standards Institute). The standard allowed portable control of video terminals. Support has been ubiquitous in Unix terminals since the 1980s and was added to Windows 10 in 2016. The NO_COLOR convention was proposed in 2017 to standardize disabling colors.

tput(1), dircolors(1), lolcat(1), terminfo(5)