OSC 10 Change Dynamic Colors
Set, query and reset the default foreground and background, the cursor's color, and others.
OSC 10 ; Pt ST
Besides the palette, xterm has a set of dynamic colors, each with its own OSC number:
Ps | Color |
|---|---|
10 | the default foreground, used by text with no SGR color |
11 | the default background |
12 | the cursor |
13, 14 | the mouse pointer’s foreground and background |
15, 16, 18 | the Tektronix window’s foreground, background and cursor |
17, 19 | the background and foreground of selected text |
OSC Ps ; Pt ST sets color Ps to Pt, in any form X11’s XParseColor accepts, and Pt of ? asks for it; the answer is OSC Ps ; rgb:rrrr/gggg/bbbb, ended as the question was. OSC 1Ps ST, that is OSC 110 ST to OSC 119 ST, puts color Ps back as it started.
A sequence can carry more than one color: each further ; moves on to the next number, so OSC 10 ; red ; blue ST sets the foreground and the background, and OSC 10 ; ? ; ? ST asks for both. An empty one is skipped, so OSC 10 ; ; blue ST sets only the background (ChangeColorsRequest, ReportColorRequest, ResetColorsRequest). Unlike the palette, neither DECSTR nor RIS resets them.
A program asks for the background, OSC 11 ; ? ST, to find out whether it is running on a light or a dark terminal and choose its own colors to suit.
Where these colors start is the host’s choice. The cases are run in a terminal given a default xterm’s: black text on white, with the cursor and the mouse pointer in the foreground color (charproc.c). That is what the answers below report; it is not how this site draws the screens.
libghostty-vt has 10, 11 and 12, and 110 to 112. It ignores the rest, so a question about the mouse pointer goes unanswered, and a chain of questions that runs past 12 stops there. It also passes over an empty color without moving on to the next number, so OSC 10 ; ; blue ST sets its foreground. Those cases are known differences.
Validation
OSC10-1: Ask for the default colors
\e]10;?\a
\e]11;?\e\\
|____|
reply \e]10;rgb:0000/0000/0000\a\e]11;rgb:ffff/ffff/ffff\e\\
OSC10-2: And the cursor’s
\e]12;?\a
|____|
reply \e]12;rgb:0000/0000/0000\a
OSC10-3: Change the foreground
\e]10;#ff8000\a
\e]10;?\a
|____|
reply \e]10;rgb:ffff/8080/0000\a
OSC10-4: Each ; moves to the next color
\e]10;red;blue\a
\e]10;?;?\a
|____|
reply \e]10;rgb:ffff/0000/0000\a\e]11;rgb:0000/0000/ffff\a
OSC10-5: An empty one is skipped
\e]10;;blue\a
\e]10;?;?\a
|____|
reply \e]10;rgb:0000/0000/0000\a\e]11;rgb:0000/0000/ffff\a
OSC10-6: Questions and changes together
\e]10;?;red\a # ask for 10, set 11
\e]11;?\a
|____|
reply \e]10;rgb:0000/0000/0000\a\e]11;rgb:ffff/0000/0000\a
OSC10-7: Reset
\e]10;red;blue;green\a
\e]110\a
\e]112\a
\e]10;?;?;?\a
|____|
reply \e]10;rgb:0000/0000/0000\a\e]11;rgb:0000/0000/ffff\a\e]12;rgb:0000/0000/0000\a
OSC10-8: RIS leaves them alone
\e]11;red\a
\ec
\e]11;?\a
|____|
reply \e]11;rgb:ffff/0000/0000\a
OSC10-9: The mouse pointer
\e]13;?\a
|____|
reply \e]13;rgb:0000/0000/0000\a
OSC10-10: A chain past the cursor
\e]12;?;?\a # the cursor, then the pointer
|____|
reply \e]12;rgb:0000/0000/0000\a\e]13;rgb:0000/0000/0000\a