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Mode 2031 color scheme reporting
Private mode 2031 enables unsolicited notifications when the terminal's color scheme changes between dark and light. When enabled, the terminal sends
CSI ? 997 ; Ps n (DECDSR) whenever the scheme changes, where Ps=1 for dark and Ps=2 for light.
Applications can also synchronously query the current scheme via CSI ? 997 n (DECDSR 997). This solves a longstanding problem for TUI applications that need to adapt their color palette to the terminal's dark/light mode. Supported by iTerm2 (3.6.6+), tmux 3.6, Contour, foot, and kitty.How this is tested: Check DECRPM for mode 2031. Fallback: query current scheme via
DECDSR 997 and check for response.Analysis2026-03-26
Supported by 1 of 18 backends (6%)
Terminal Applications
| Terminal | Version | Support | Notes |
|---|---|---|---|
| cmux | ✓ yes | DECRPM: mode reset | |
| iTerm2 | 3.6.9 | ? unknown | |
| Ghostty | 1.3.1 | ? unknown | |
| VS Code | 1.112.0 | ? unknown | |
| Cursor | 2.6.21 | ? unknown | |
| Warp | 0.2026.03.18.08.24.03 | ? unknown | |
| Terminal.app | 2.15 | ? unknown | |
| Kitty | 0.46.2 | ? unknown | Mode 2031 not exposed via Python batch bridge |
Headless Backends
Parser correctness only — a ✓ means the parser accepts the sequence.
| Backend | Version | Support | Notes |
|---|---|---|---|
| WezTerm | 0.1.0-fork.5 | ~ partial | Mode 2031 not exposed in headless mode |
| Alacritty | 0.26.0 | ✗ no | Mode 2031 not implemented in alacritty |
| vt100.js | 0.2.1 | ✗ no | Not implemented — pure TypeScript emulator |
| vterm | 0.2.0 | ✗ no | Mode 2031 not implemented |
| xterm.js | 5.5.0 | ? unknown | Mode 2031 not implemented in xterm.js |
| xterm.js | 6.0.0 | ? unknown | Mode 2031 not implemented in xterm.js |
| xterm.js | 5.4.0 | ? unknown | Mode 2031 not implemented in xterm.js |
| xterm.js | 6.1.0-beta.195 | ? unknown | Mode 2031 not implemented in xterm.js |