24-bit truecolor (semicolons)

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Experimental

24-bit truecolor (semicolons) uses SGR 38;2 and 48;2 with semicolon-separated RGB values to set foreground and background to any of 16.7 million colors.

Syntax

CSI 38;2;r;g;b m    SGR — Set foreground to RGB color
CSI 48;2;r;g;b m    SGR — Set background to RGB color

Formal syntax

SGR-fg-rgb = 0x1b, "[", "38", ";", "2", ";", r, ";", g, ";", b, "m" ;
SGR-bg-rgb = 0x1b, "[", "48", ";", "2", ";", r, ";", g, ";", b, "m" ;
r          = digit, { digit } ;                    (* red: 0-255 *)
g          = digit, { digit } ;                    (* green: 0-255 *)
b          = digit, { digit } ;                    (* blue: 0-255 *)
digit      = "0" | "1" | "2" | "3" | "4"
         | "5" | "6" | "7" | "8" | "9" ;

Parameters

Parameter	Description
`r`	Red component (0-255)
`g`	Green component (0-255)
`b`	Blue component (0-255)

Description

The semicolon-separated truecolor syntax is the most widely supported form of 24-bit RGB color in terminals. It extends the ECMA-48 SGR 38/48 color mechanism with 2 as the color space indicator, followed by the red, green, and blue components.

This syntax deviates from the ITU-T T.416 standard, which specifies colons as sub-parameter separators (see the colon variant). However, the semicolon form was adopted first by terminal emulators and has broader support.

Colors set via RGB are not affected by palette changes and always represent the exact specified color.

Examples

printf '\e[38;2;255;100;0mOrange text\e[0m\n'
printf '\e[48;2;0;0;128mNavy background\e[0m\n'
printf '\e[38;2;255;255;255;48;2;0;0;0mWhite on black\e[0m\n'

Specifications

Specification	Section
XTerm ctlseqs	—

Terminal support

Terminal	Support	Version	Notes
Terminal Emulators
Alacritty	✓	Yes	SGR 38;2;r;g;b - parsed by vte crate v0.15.0
Bobcat	?	?	Implemented in external TerminalCtrl library, not in Bobcat source code
contour	✓	v0.1.0	SGR 38;2;r;g;b and 48;2;r;g;b
foot	✓	Yes	SGR 38;2;r;g;b handled in csi.c:182-192
Ghostty	✓	v1.0.0
iTerm2	✓	v20260216-nightly
Kitty	✓	Yes	Present since early versions
Konsole	✓	Yes	SGR 38;2;r;g;b / 48;2;r;g;b / 58;2;r;g;b in src/Vt102Emulation.cpp:575-582
mintty	✓	Yes	SGR 38;2;r;g;b and 48;2;r;g;b fully implemented at termout.c:2214-2222 and 2273-2285
mlterm	✓	rel-3_1_6
PuTTY	✓	0.71	SGR 38;2;r;g;b implemented in commit a4cbd3df
Rio	✓	v0.0.3
rxvt-unicode	✓	rxvt-unicode-9.25
st	✓	0.5
terminology	✓	v1.4.0	Approximated to 256-color palette
VT100	✗	No
VTE	✓	Yes	SGR 38;2;r;g;b supported in collect_sgr_color semicolon branch
WezTerm	✓	Yes	Implemented via SGR 38;2;r;g;b - see wezterm-escape-parser/src/csi.rs:2524-2535
Windows Terminal	✓	Yes	SGR 38;2;r;g;b handled in _SetRgbColorsHelper via GraphicsOptions::RGBColorOrFaint
xterm	✓	Yes	SGR 38;2;r;g;b supported for compatibility with KDE konsole. Requires OPT_DIRECT_COLOR for true 24-bit, otherwise uses closest palette match
xterm.js	✓	0.3
Multiplexers
cy	✓	Yes
GNU Screen	✓	v.5.0.0
tmux	✓	2.2	SGR 38;2;r;g;b and 48;2;r;g;b
tuios	✓	v0.0.15
Zellij	✓	v0.12.0

Syntax​

Parameters​

Description​

Examples​

Specifications​

Terminal support​

See also​