Colors

Otty supports four color depths, layered: 24-bit truecolor, 256-color indexed, ANSI 16, and the default (no SGR).

The 16-color palette

The first 16 entries of the palette are the classic ANSI colors plus their "bright" variants:

Index	Name	Index	Name
0	black	8	bright black
1	red	9	bright red
2	green	10	bright green
3	yellow	11	bright yellow
4	blue	12	bright blue
5	magenta	13	bright magenta
6	cyan	14	bright cyan
7	white	15	bright white

Set via SGR 30–37 / 40–47 (regular) and 90–97 / 100–107 (bright). The actual RGB values come from the active Theme.

The 256-color palette

Indices 0–15: same as above. Indices 16–231: a 6×6×6 RGB cube. Indices 232–255: 24 shades of grey.

Set with SGR 38;5;<n> (foreground) or 48;5;<n> (background). See SGR.

24-bit truecolor

SGR 38;2;<r>;<g>;<b> (foreground) or 48;2;<r>;<g>;<b> (background). Each channel 0–255.

Otty advertises truecolor via COLORTERM=truecolor in the environment. Programs that gate on this env var (Neovim, modern shells) light up automatically.

Default colors

SGR 39 resets foreground to the theme default; SGR 49 resets background. These are not "black" or "white" — they're whatever the theme defines as default.

Bold-is-bright

A legacy convention: rendering bold text in the brightness palette. Off in Otty by default. Toggle with bold-is-bright = on in Themes.

Color reporting (OSC 4 / 10 / 11)

Programs can query and modify palette entries at runtime:

• OSC 4 ; <index> ; <spec> — set / query palette entry
• OSC 10 ; <spec> — set / query default foreground
• OSC 11 ; <spec> — set / query default background

A query is <spec> = "?"; the terminal replies with the current value.

See also

• SGR — the command that uses these.
• Theme Format — how to define your own palette.