rdmsm4x-changelog-20260904-0012-claude-statusline-v2.4.0-switchable-model-chip-themes

[2026-09-04 00:12 EDT · rdmsm4x]

Summary: Model-chip colours are no longer hardcoded. v2.4.0 ships 8 themes switchable per host, with a live in-terminal preview and a fleet-wide switcher. Installed on all six hosts. The default is unchanged (frost) — nobody's status line changes appearance until they choose a theme.

Why a theme table instead of just recolouring

Rich asked for "darker orange background with black letters". That specific pair is fine — but the failure mode it invites is not, so the colours are now data that gets measured rather than literals someone eyeballs.

Every (background, foreground) pair was checked with the WCAG 2.1 relative- luminance formula before being encoded. The chip is short bold text, so AA-large (3.0:1) is the floor and AA (4.5:1) is the target:

theme	character	worst pair
`frost`	Nord Frost blues, shaded by family — default	3.50:1
`ember`	burnt orange, black letters — the requested look	4.87:1
`amber`	bright amber/gold, black letters	8.31:1
`aurora`	full Nord Aurora, a distinct hue per family	3.55:1
`magma`	deep volcanic orange, light-on-dark	4.16:1
`slate`	quiet Nord polar night, snow letters	4.93:1
`snow`	light chip, dark letters (light terminals)	6.06:1
`mono`	no chip at all — the pre-2.3.0 look	n/a

Nothing fails. Worth noting: the weakest pair on the fleet is the shipped default, frost/Opus at 3.50:1 — passing, but the floor. ember is stronger.

Usage

bash ~/.claude/statusline.sh --chip-preview        # see all 8, in your terminal
bash ~/.claude/statusline.sh --set-theme ember     # this host
zsh  ~/.claude/canonical/statusline_theme_fleet.zsh ember    # all six hosts
zsh  ~/.claude/canonical/statusline_theme_fleet.zsh --show   # report per host

Resolution order: $CC_STATUSLINE_THEME → ~/.claude/statusline-theme → frost. The env var makes a theme trialable for one session without touching any file. The theme file is per-host, so one machine can deliberately differ.

Verification

All 8 themes × 4 model families render; emitted ANSI RGB compared programmatically against the contrast-checked hex — exact match on every pair sampled across frost/ember/amber/magma/snow/slate.
mono emits no 48;2; background sequence, and suppresses the chip's pad spaces so there is no stray coloured gap. Asserted, not assumed.
An invalid theme name falls back to frost and still renders the model — a typo in the theme file must not cost the model readout. --set-theme rejects unknown names with exit 1.
Perf held to parity, which required a fix: the first cut called $(model_family …), forking a subshell on every keystroke — measured ~2.8ms per render, the same order as the git call this script deliberately avoids. Rewritten to assign $FAMILY instead of echoing. 30 renders: 2.748s (v2.4.0) vs 2.744s (v2.3.0).
Post-push all 5 remotes report sha 7a0374064f1855016235726c17068635592da7b466071849697c32e25251ae65. Live remote render with CC_STATUSLINE_THEME=ember on rdmbair15m5 and rdmpw3265m emits ESC[48;2;180;101;60m = #B4653C, correct.
statusline_theme_fleet.zsh --show: all six hosts report frost.

Files

~/.claude/canonical/statusline.sh → v2.4.0, sha 7a03740… (555)
~/.claude/canonical/statusline.sha256
~/.claude/canonical/statusline_theme_fleet.zsh — new (555)
~/.claude/statusline.sh on all 6 hosts
Dead code removed: the v2.3.0 hardcoded BG_N*/FG_* palette block, now superseded by the theme table (0 references remain).

Undo

~/.claude/backups/statusline.sh.v2.3.0-bak-20260904-0009 (rdmsm4x) and statusline.sh.bak-20260904-001* on each remote. Revert canonical, not just the live file — statusline-verify.sh restores from canonical at SessionStart.

Outstanding

Apple Notes entry pending for this and the v2.3.0 changelog — session is launchctl managername = Background, so notes_changelog.zsh correctly refuses. Publish both from an Aqua session.
No theme has been chosen; the fleet is on the frost default by design.