[skarim]

Aligns gh-stack's look with GitHub's brand and the GitHub Copilot CLI: colors now come from Primer Brand, and the full-screen view, modify, and submit screens paint GitHub's dark or light canvas behind themselves.

Functionality and user impact

• GitHub canvas in full-screen screens. view, modify, and submit set the terminal to GitHub's canvas while they're open, like the Copilot CLI: #0d1117 with #f0f6fc text on dark terminals, #ffffff with #1f2328 on light ones. Painting needs a truecolor terminal. NO_COLOR, non-terminal output, and the new GH_STACK_BACKGROUND=terminal keep the terminal's own colors, and in tmux only the current pane is painted. GH_STACK_THEME also picks the canvas.
• The terminal's colors come back. They're reset when a screen closes (including on Ctrl+C, signals, and panics) and while $EDITOR is open from submit. gh-stack also records the terminal's colors before painting and restores any the reset misses, such as colors set at runtime by pywal or base16-shell, or terminals that ignore the reset. Terminals that follow automatic light/dark switching keep following it.
• Primer Brand colors. The teal accent becomes Primer Brand blue, and the PR-state colors move to Brand shades that meet WCAG AA contrast on GitHub's canvases. Primary actions (the submit and stack buttons, the selected Ready/Draft option, the CREATE PR switch, and completed merge steps) use the Brand green button style.
• Everything else keeps the terminal's background. Plain command output and the inline checkout and merge screens use the new colors but never paint the background.
• Preview and logo. The submit description preview uses the palette and GitHub's syntax highlighting, and the header logo switches to the dark Invertocat on light backgrounds.

Before images use a typical terminal theme. After images of the full-screen screens show the GitHub canvas.

Screen	Before	After
gh stack view, dark terminal
gh stack view, light terminal
gh stack submit, dark terminal
gh stack submit, light terminal
Description preview, dark terminal
Description preview, light terminal
gh stack modify, dark terminal
gh stack merge, dark terminal
gh stack checkout, dark terminal
Command output, dark terminal
Command output, light terminal

Key areas to review

• internal/theme/canvas.go: CanvasOutput paints right after the alternate screen is entered and restores colors right before it's left, which covers exits, signals, panics, and tea.ExecProcess (including $EDITOR) without hooks in the models. planRestore probes the terminal before painting and plans each color's restore: a reset when that brings the color back, so theme changes made while a screen is open still apply, and otherwise an explicit set. canvasSupported decides when to paint.
• cmd/utils.go: runFullScreenTUI and fullScreenCanvas, now used by view, modify, and submit.
• internal/tui/submitview/preview.go: editorCommand pins $EDITOR's stdout to the terminal, because tea.ExecProcess would otherwise hand it the canvas wrapper. markdownStyle recolors the preview.
• internal/theme/theme.go: the palette (GitHub neutrals, Primer Brand hues, the primary fill, and badge pairs), now the only place hex values live.
• internal/tui/submitview/styles.go, internal/tui/mergeview/view.go, and internal/tui/checkoutview/styles.go: primary actions, state badges, the merge stepper, and the checkout status bar switched to theme roles.
• internal/theme/theme_test.go and internal/theme/canvas_test.go: contrast checks for every color pairing, and color restoration, including a real Bubble Tea program that runs an external command.

Testing

Build, go vet ./... (also with GOOS=windows), and the full race-enabled suite (go run ./scripts/test -workers 4) pass. The built binary was also run in a PTY against a terminal emulator that tracks color state: colors came back after q, Ctrl+C, Esc, and SIGTERM on dark, light, pywal-style, tmux, and reset-ignoring terminals, and the opt-out and plain output never painted. Manually tested in real terminals, and design review is complete.

[Copilot]

🔵 Needs a closer look

Terminal-wide color restoration is emulator-dependent, and unresolved restoration and contrast issues require fixes and human validation.

4 open issues

• Restore terminal colors before opening the editor · New
• Theme changes are overwritten by stale saved colors · New
• Dark purple fails contrast for merged state label · New
• Merged-status squares fail selected-row contrast · New

What changed in this PR

Aligns gh-stack’s command output and terminal interfaces with GitHub’s Primer Brand palette, adding GitHub backgrounds to full-screen screens.

Changes:

• Centralize palette roles, status badges, and primary-action colors.
• Add full-screen canvas painting, color restoration, and a background opt-out.
• Refresh Markdown previews and logos, with supporting tests and documentation.

File	Description
README.md	Document canvas behavior, theme controls, and recovery.
internal/​tui/​submitview/​styles.go	Apply shared badges and primary-action colors.
internal/​tui/​submitview/​styles_test.go	Check badge and primary-action rendering.
internal/​tui/​submitview/​screen.go	Update accent-color terminology in comments.
internal/​tui/​submitview/​preview.go	Theme Markdown previews and preserve editor terminal output.
internal/​tui/​submitview/​preview_test.go	Cover preview colors, highlighting, and editor setup.
internal/​tui/​submitview/​editor.go	Update toggle and focus-style comments.
internal/​tui/​shared/​theme.go	Expose shared palette and badge aliases.
internal/​tui/​shared/​render.go	Update current-branch styling terminology in comments.
internal/​tui/​shared/​logo.go	Choose the logo variant for the detected background.
internal/​tui/​shared/​header.go	Update the default icon-color comment.
internal/​tui/​shared/​header_test.go	Verify background-aware logo selection.
internal/​tui/​mergeview/​view.go	Apply primary and inverse stepper colors.
internal/​tui/​mergeview/​model_test.go	Check stepper color roles.
internal/​tui/​checkoutview/​styles.go	Use centralized dim status colors.
internal/​theme/​theme.go	Define Primer Brand colors, fills, and badges.
internal/​theme/​theme_test.go	Add palette contrast checks.
internal/​theme/​canvas.go	Implement canvas painting and terminal-color restoration.
internal/​theme/​canvas_test.go	Cover canvas transitions and restoration behavior.
internal/​modify/​preconditions.go	Use accent highlighting in guidance.
internal/​modify/​apply.go	Use accent highlighting in recovery instructions.
internal/​config/​testing.go	Rename the test color hook to accent.
internal/​config/​config.go	Wire accent coloring into configuration and messages.
internal/​config/​color_test.go	Update accent-color coverage.
docs/​src/​content/​docs/​reference/​cli.md	Document canvas and palette environment variables.
cmd/​worktree_utils.go	Use accent highlighting for navigation guidance.
cmd/​view.go	Route full-screen viewing through the canvas wrapper.
cmd/​utils.go	Add shared full-screen canvas integration.
cmd/​utils_test.go	Cover canvas eligibility and opt-out behavior.
cmd/​unstack.go	Use accent highlighting for flag guidance.
cmd/​sync.go	Use accent highlighting for follow-up commands.
cmd/​submit.go	Use the canvas wrapper and accent highlighting.
cmd/​rebase.go	Use accent highlighting in conflict instructions.
cmd/​rebase_worktree.go	Use accent highlighting for push guidance.
cmd/​push.go	Use accent highlighting for follow-up commands.
cmd/​modify.go	Use the canvas wrapper and accent highlighting.
cmd/​merge.go	Use accent highlighting in merge guidance.
cmd/​init.go	Use accent highlighting in setup guidance.
cmd/​checkout.go	Use accent highlighting in checkout guidance.
cmd/​alias.go	Use accent highlighting in alias messages.
cmd/​add.go	Use accent highlighting in branch guidance.
AGENTS.md	Document palette ownership and canvas lifecycle conventions.
.github/​copilot-instructions.md	Add theme and full-screen integration guidance.

_{Review effort: Max}