wire / terminal-osc / 12

OSC 12 — Set / query text cursor color

OSC 12 ; spec ST sets the text cursor's color; OSC 12 ; ? ST queries it, replied as OSC 12 ; rgb:RRRR/GGGG/BBBB ST. This colors the cursor block/bar itself, independent of the default foreground (OSC 10) and background (OSC 11).

terminal-osc kind control-sequence status de-facto verification verified tier B terminal-escape@1

aka: set cursor color · query cursor color · OSC 12 · ESC ] 12

frame

OSC introducer: \x1b] ESC ] (0x1B 0x5D)

terminator (ST|BEL): ST \x1b\ · BEL \x07

parameters / subcommands

id	name	bytes (ST)	meaning
set	Set cursor color	\x1b]12;#ff0000\x1b\	OSC 12 ; spec ST sets the text cursor color (X11 name or rgb:/# form).
query	Query cursor color	\x1b]12;?\x1b\	OSC 12 ; ? ST asks for the cursor color; reply OSC 12 ; rgb:RRRR/GGGG/BBBB ST.

gotchas

OSC 12 colors only the CURSOR; OSC 10/11 set text fg/bg. They are independent.
The cursor's SHAPE (block/underline/bar) and blink come from DECSCUSR (CSI Ps SP q) and DEC mode 12, not from OSC 12.
Query reply is 16-bit-per-channel rgb:RRRR/GGGG/BBBB; read with a timeout.
Reset with OSC 112 (reset cursor color) and restore on exit.
Some terminals invert the cell under a block cursor regardless of OSC 12, so the configured color may only show on bar/underline cursors.

provenance

source: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
version: xterm ctlseqs, patch #410, 2026/04/19
retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

#summary — https://invisible-island.net/xterm/ctlseqs/ctlseqs.html xterm ctlseqs: Ps = 1 2 -> Change text cursor color to Pt; '?' queries and the terminal reports it back.

OSC 12 — Set / query text cursor color

frame

parameters / subcommands

gotchas

provenance

see also