Colors

Status: xterm, with an Extension for scheme reports.

OSC 4 and OSC 10–19 change and query the colors an emulator uses for the palette, default foreground and background, cursor, and selection. They are the only portable way for an application to discover whether it is running on a dark or light background.

Syntax

Palette: OSC 4 and OSC 5

OSC 4 ; index ; spec ST         set palette entry
OSC 4 ; index ; ? ST            query palette entry
OSC 5 ; index ; spec ST         set special color (bold, underline, blink, reverse)
OSC 104 ; index ST              reset palette entry
OSC 104 ST                      reset entire palette
OSC 105 ; index ST              reset special color

index ranges over 0–255 (or 0–15 in emulators that lock the extended cube). Several index ; spec pairs may appear in one string. xterm's OSC 5 indices are 0 bold, 1 underline, 2 blink, 3 reverse, 4 italic; few emulators implement them.

Dynamic colors: OSC 10–19

OSC 10 ; spec ST    default foreground
OSC 11 ; spec ST    default background
OSC 12 ; spec ST    cursor color
OSC 13 ; spec ST    pointer foreground
OSC 14 ; spec ST    pointer background
OSC 15 ; spec ST    Tektronix foreground
OSC 16 ; spec ST    Tektronix background
OSC 17 ; spec ST    highlight (selection) background
OSC 18 ; spec ST    Tektronix cursor
OSC 19 ; spec ST    highlight (selection) foreground
OSC 110–119 ST      reset the corresponding color

A spec of ? queries instead of sets. Successive values in one string apply to successive selectors: OSC 10 ; fg ; bg ST sets 10 and 11.

Color specifications

spec is parsed like XParseColor:

rgb:RR/GG/BB          1–4 hex digits per channel, scaled to the digit count
rgb:RRRR/GGGG/BBBB
#RGB #RRGGBB #RRRRGGGGBBBB
rgbi:R/G/B            floating point 0.0–1.0
name                  X11 color names such as red, DarkSlateGray

Replies use the 16-bit rgb:RRRR/GGGG/BBBB form regardless of how the color was set. Emulators without the X11 color database reject names.

Query and reply

Application:  OSC 11 ; ? ST
Terminal:     OSC 11 ; rgb:1e1e/1e1e/1e1e ST

The reply uses the same terminator the query used in xterm; other emulators always reply with ST or always with BEL. Parse both.

Behavior

• Palette changes affect cells already on screen: the palette is indexed at render time. Truecolor (SGR 38;2) cells are unaffected.
• Reset (104, 110–119) restores the configured value, not the value before the last OSC. Applications cannot restore an unknown prior state; see Modes: ownership and cleanup.
• Queries are reports and share every hazard described in Queries and reports. Under tmux, OSC 10/11 queries are answered by tmux from its own idea of the outer terminal, which may be stale or empty.
• Some emulators (Konsole, VTE) treat OSC 4 as changing the current profile only until reset; others (kitty) can be told to persist.

Color-scheme reports: DEC mode 2031

Status: Extension (Contour).

Querying OSC 11 gives one color; it does not say whether the user intends a dark or light theme. Contour introduced a mode that reports the theme as a category and notifies on change:

CSI ? 2031 h          enable unsolicited theme reports
CSI ? 2031 l          disable
CSI ? 996 n           query the current theme
CSI ? 997 ; 1 n       report: dark
CSI ? 997 ; 2 n       report: light

The report is a DSR-style CSI, not an OSC, and is emitted whenever the emulator's theme changes while the mode is set. Applications should treat it as a hint and still honor explicit NO_COLOR or their own configuration.

Probe

tools/query bg                # OSC 11 ; ? — reply is ^[]11;rgb:rrrr/gggg/bbbb^[\
tools/query fg
printf '\033]4;1;rgb:ff/00/ff\033\\'; printf '\033[31mred is now magenta\033[0m\n'
printf '\033]104;1\033\\'
printf '\033[?2031h'; printf '\033[?996n'   # expect CSI ? 997 ; 1 n or ; 2 n

Sources

• XTerm Control Sequences, OSC 4/5/10–19
• XParseColor(3) color formats
• Contour: dark and light mode detection
• kitty: color control
• Ghostty VT reference
• foot: escape sequences
• WezTerm escape sequences
• iTerm2 proprietary escape codes
• tmux(1)

Separately tracked behavior

Dynamic color addressing under reverse video

Feature ID: osc-dynamic-colors-reverse-video. OSC 10/11 address displayed foreground/background under DECSCNM as xterm does.

Compatibility

Feature support by terminal. Imported claims have not been reverified; unknown is not unsupported.

Feature / stable ID	Alacritty	Apple Terminal	ConPTY (conhost)	Contour	DomTerm	foot	Ghostty	iTerm2	kitty	Konsole	mintty	mlterm	PuTTY	Revenant	RLogin	st	tmux	rxvt-unicode	VTE	wayst	WezTerm	Windows Terminal	xterm	xterm.js
2031 color scheme reports dec-mode-2031-color-scheme-reports	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Supported	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 4 set osc-4-palette-set	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	PartialImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified
OSC 4 query osc-4-palette-query	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	PartialImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified
OSC 10/11 set osc-10-11-default-colors-set	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	Unknown	Partial	Unknown	Unknown	PartialImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified
OSC 10/11 query osc-10-11-default-colors-query	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	Unknown	Partial	Unknown	Unknown	PartialImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified
OSC 12 cursor osc-12-cursor-color	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified
OSC 17/19 selection osc-17-19-selection-colors	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown
104/110/111 reset osc-104-110-111-color-reset	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified
X11 color names osc-x11-color-names	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown
Enable/disable special color osc-6-xterm-special-color	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Default foreground color osc-10-default-foreground-color	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Default background color osc-11-default-background-color	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Pointer foreground osc-13-pointer-foreground	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Pointer background osc-14-pointer-background	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Tektronix foreground osc-15-tektronix-foreground	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Tektronix background osc-16-tektronix-background	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Highlight (selection) background osc-17-highlight-selection-background	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Tektronix cursor osc-18-tektronix-cursor	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Highlight (selection) foreground osc-19-highlight-selection-foreground	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Enable/disable special color osc-106-enable-disable-special-color	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Set or query palette color index osc-4-palette	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Set or query special color (bold, underline, blink, reverse) osc-5-special-colors	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Reset palette color(s) osc-104-palette-reset	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Reset special color(s) osc-105-special-colors-reset	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Reset the dynamic color set by 10–19 osc-110-119-dynamic-colors-reset	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Query light or dark color scheme csi-996-n-color-scheme-query	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Supported	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Dynamic color addressing under reverse video osc-dynamic-colors-reverse-video	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown