OSC 10 — Set / query default foreground color

frame

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

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

parameters / subcommands

gotchas

• The query REPLY uses 16-bit-per-channel rgb:RRRR/GGGG/BBBB; do not assume it matches the width you wrote when setting.
• OSC 10/11/12 consume SUCCESSIVE parameters: 'OSC 10 ; fg ; bg ST' sets fg via 10 and bg via the implicit 11. To set only fg, send just one parameter.
• OSC 10 is the DEFAULT foreground (used where no SGR color is active); it is NOT a palette index — use OSC 4 for indexed colors and SGR 38 for per-run colors.
• Reading the query reply requires reading from the tty with a timeout, or the read blocks if the terminal doesn't answer.
• Reset to defaults with OSC 110 (reset foreground); restore on exit so the user's theme isn't left altered.

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 0 -> Change VT100 text foreground color to Pt. A '?' queries the color, reported back as a control sequence. Consecutive OSC 10/11/12... consume successive color parameters.

see also

• terminal-osc/11
• terminal-osc/12
• terminal-osc/4