Color Theme

POUNCE’s terminal output uses one tiger / rust / warm palette across every colored surface — the iteration table, the branded wordmark, and the interactive debugger. This page is the single reference for what the colors mean; the palette itself lives in pounce-common::style (a pure, unit-tested module — no I/O, no globals).

For the environment variables that turn color on/off (NO_COLOR, CLICOLOR_FORCE, RUST_LOG, POUNCE_LOG_FORMAT) see Solver Options → Logging and colored output.

The palette

Two further surfaces reuse these or a small extension:

Where the colors appear

The iteration table

Two orthogonal channels encode solver state on each row:

• Background = restoration kind, keyed off the row’s alpha_primal_char tag:
  • s soft-stay → tan, S soft-exit → amber, R hard (and the dedicated restoration phase’s r-suffixed rows) → deep rust.
  • Normal (non-restoration) rows have no background.
  • Tiny-step tags (t/T) deliberately get no background — that stall is shown by the foreground instead.
• Foreground = a smooth gradient on the primal step length α ∈ [0, 1] (a visual stalling cue):
  • Normal rows: black (α = 1, full step) → hot red (α → 0).
  • Restoration rows: cream (α = 1) → bright yellow (α → 0), so the text stays legible on the dark background.
  • α is clamped to [0, 1]; a non-finite α is treated as a full step (no false stalling alarm).

So at a glance: a dark row means restoration (its shade tells you which kind), and redder / yellower text means a shorter step (the solver is struggling to move).

The branded wordmark (pounce logo)

Printed atop a normal solve and at the top of the debugger REPL. The POUNCE block letters carry a top-lit steel sheen (light silver #d2d6dc at the top row fading to dark steel #5c6068 at the bottom), and three diagonal molten claw slashes rake across them, glowing bright yellow → tiger-orange → deep red top-to-bottom — the project logo’s forged-metal-with-lava look.

The interactive debugger

The REPL open banner (--debug) reuses the same wordmark, then a command cheat-sheet whose shortcut keys are tiger-orange, the interior-point debugger line and the help hint are gold, and the descriptive gloss is dim grey. Pause banners and command output are otherwise uncolored. (--debug-json emits no color — its stdout is a pure JSON channel.)

viz kkt / viz L open in the external Plotly viewer (pounce-dbg-viz), which is a separate visual language: the sparse-matrix heatmaps use a diverging red–blue scale keyed on entry value (sign + magnitude), not the terminal palette.

Logs

WARN-level log lines (on stderr) take the tiger-orange accent; other levels use the subscriber’s defaults.

Terminal support & downgrade

• Truecolor (24-bit) is used when the terminal advertises it via COLORTERM — every color above is emitted as exact RGB.
• 256-color terminals get a graceful fallback: each RGB color snaps to the nearest xterm 6×6×6 cube color (downgrade / nearest_ansi256). The theme still reads correctly, just quantized.

When color is emitted

Color is opt-out and TTY-aware:

• The iteration table is colored only when stdout is a terminal (via anstream::AutoStream, which strips escapes from redirected output while keeping identical column alignment).
• The debugger banner is colored only when stderr is a terminal.
• NO_COLOR (any value) disables color everywhere; CLICOLOR_FORCE forces it even into a non-terminal sink. See Solver Options.

Because the policy is consistent, redirected logs/output are always plain text — safe to diff, grep, and ingest.

For contributors

Add or change colors in pounce-common::style, never with inline ANSI: the constants, the α-gradient (alpha_gradient_rgb), the restoration mapping (resto_background_rgb), the composed iteration_row_style, and the truecolor downgrade all live there and are unit-tested without a TTY. Print sites style through anstyle + anstream (or, for the debugger banner on stderr, gate on stderr().is_terminal() and NO_COLOR). Keep the two iteration-table channels — background = restoration kind, foreground = step length — orthogonal.