feat(theme): a third bundled palette, Graphite, between dark and light

crates/moon-ui-components/src/moon/theme.rs

@@ -319,6 +319,17 @@ impl MoonThemeConfig {
             .expect("bundled moon-light theme must parse")
     }
 
+    /// The middle theme — [`MoonPalette::GRAPHITE`] on the DARK side, `LIGHT` on the light side.
+    ///
+    /// `mode` is `Dark`, and that is not a placeholder: Graphite IS a dark theme, just a softer
+    /// one, so it takes the dark colour set everywhere a consumer branches on
+    /// [`MoonPalette::is_light`]. A host that needs to know Graphite specifically asks its own
+    /// settings, not this config's `mode`.
+    pub fn moon_graphite() -> Self {
+        toml::from_str(include_str!("../../themes/moon-graphite.toml"))
+            .expect("bundled moon-graphite theme must parse")
+    }
+
     /// Set the font delta on both themes, refusing a value that cannot render.
     ///
     /// [`MoonScale::font_delta`] is added directly into every text metric, so a non-finite value

crates/moon-ui-components/src/moon/theme/tests.rs

@@ -24,6 +24,7 @@ fn rgb_of(color: gpui::Hsla) -> u32 {
 fn selection_inks_are_readable_on_the_surface_each_one_lands_on() {
     for (name, palette) in [
         ("dark", MoonPalette::TERMINAL),
+        ("graphite", MoonPalette::GRAPHITE),
         ("light", MoonPalette::LIGHT),
     ] {
         let tokens = MoonThemeTokens {
@@ -115,3 +116,13 @@ fn a_non_finite_font_delta_is_replaced_while_zero_is_kept() {
         "zero font delta is 'no adjustment', a real setting - it must be kept"
     );
 }
+
+/// Catches `theme.rs:MoonThemeConfig::moon_graphite` drifting from its bundled TOML palette.
+/// A const and its bundled theme file must agree, or Graphite paints a different palette than planned.
+#[test]
+fn graphite_theme_config_matches_the_bundled_dark_and_light_palettes() {
+    let config = MoonThemeConfig::moon_graphite();
+    assert_eq!(config.dark.palette, MoonPalette::GRAPHITE);
+    assert_eq!(config.light.palette, MoonPalette::LIGHT);
+    assert_eq!(config.mode, crate::moon::foundation::ThemeMode::Dark);
+}

crates/moon-ui-components/src/moon/tokens.rs

@@ -198,6 +198,86 @@ impl MoonPalette {
         yellow: 0xB8860B,
     };
 
+    /// The middle theme: mid-tone neutral surfaces with light ink, between [`Self::TERMINAL`]
+    /// and [`Self::LIGHT`].
+    ///
+    /// It is a DARK palette by measurement, not by declaration — `shell` has a luma of 54.5, so
+    /// [`Self::is_light`] answers `false` and every consumer that branches on it (`MoonTone`,
+    /// `theme_colors`, a host's own logo and chart-colour picks) takes the dark arm with no new
+    /// code. That is the whole reason this ships as a palette rather than a third `ThemeMode`.
+    ///
+    /// Surfaces sit at HSL-L 21.8–29.8%, which is 5.4× `TERMINAL`'s relative luminance — visibly
+    /// softer than the near-black dark theme while staying unmistakably dark. Lighter was tried
+    /// and does not work: at a shell of HSL-L 31.6% even `text` falls under 4.5:1 on the matching
+    /// `panel_high`, and any conforming `text_muted` would then have to be LIGHTER than `text`,
+    /// erasing the muted/normal distinction the palette exists to express.
+    ///
+    /// `text_muted` is deliberately NOT the dark palette's `0x7D7669`: that ink measures 3.03:1
+    /// here and is unreadable. Lifting it is the fix — a mid-tone surface needs its own muted
+    /// ink, never a third colour table.
+    ///
+    /// Measured with [`contrast_ratio`] against the WCAG floor of 4.5:1 — `text` 10.35 / 10.35 /
+    /// 8.22 and `text_muted` 6.13 / 6.13 / 4.87 on `shell` / `window` / `panel`. Accent hues are
+    /// carried over from `TERMINAL` unchanged, and `green` and `red` are lifted in lightness only,
+    /// at the same hue.
+    ///
+    /// `red` is lifted further than it looks like it needs to be, because on the dark side it is
+    /// not only a fill: `Button::danger_fg` resolves to `red` for any palette that is not light,
+    /// and the outline danger button paints that ink over a transparent `shell`. A saturated red
+    /// cannot reach the required luminance there at all — pure `0xFF0000` is only 0.21 — so the
+    /// choice is a paler red or unreadable danger text. At `0xFA8A8C` the pairing measures
+    /// 5.18 / 4.12 / 4.58 on `shell` / `panel` / `card`, which matches or beats `TERMINAL`'s own
+    /// 4.71 / 4.02 / 4.36 on every one. Do not "restore the saturation" without re-measuring that
+    /// button.
+    pub const GRAPHITE: Self = Self {
+        shell: 0x33373C,
+        shell_high: 0x3B3F45,
+        window: 0x33373C,
+        surface: 0x373B40,
+        panel: 0x41464C,
+        panel_high: 0x464B52,
+        chrome: 0x3B3F45,
+        tabbar: 0x3B3F45,
+        panel_head: 0x464B52,
+        gutter: 0x2E3236,
+        chart_bg: 0x373B40,
+        card: 0x3B3F45,
+        row_alt: 0x3B3F45,
+        head_row: 0x41464C,
+        border: 0x51565D,
+        border_soft: 0x4C5158,
+        border_card: 0x51565D,
+        border_hover: 0x646A72,
+        row_line: 0x4C5158,
+        shadow: 0x000000,
+        overlay: 0xFFFFFF,
+        on_accent: 0xFFFFFF,
+        text: 0xF1EEE8,
+        text_soft: 0xC9C5BD,
+        text_dim: 0xF1EEE8,
+        text_muted: 0xBDB9B1,
+        text_faint: 0xA8A49C,
+        table_head: 0x41464C,
+        table_body: 0x3B3F45,
+        table_selected: 0xFFB347,
+        table_hover: 0x4B5057,
+        green: 0x2FB673,
+        green_btn: 0x1E8C5B,
+        green_text: 0x2FB673,
+        red: 0xFA8A8C,
+        red_text: 0xFA8A8C,
+        red_soft_bd: 0xFA8A8C,
+        orange: 0xFF8E5A,
+        amber: 0xFFB347,
+        blue: 0x7FC9FF,
+        accent: 0xFFB347,
+        accent_fg: 0xFFCF94,
+        // A touch stronger than TERMINAL's 0.11: an 11% tint disappears into a mid grey where on
+        // near-black it reads clearly.
+        accent_tint_a: 0.14,
+        yellow: 0xFFD93D,
+    };
+
     pub fn with_legacy_defaults(mut self) -> Self {
         if self.window == 0 {
             self.window = self.shell;

crates/moon-ui-components/src/moon/tokens/tests.rs

@@ -15,6 +15,7 @@ const SELECTED_TEXT_CONTRAST_FLOOR: f32 = 4.5;
 fn selected_row_ink_stays_readable_on_the_panel_it_is_tinted_over() {
     for (name, p) in [
         ("dark", MoonPalette::TERMINAL),
+        ("graphite", MoonPalette::GRAPHITE),
         ("light", MoonPalette::LIGHT),
     ] {
         let ratio = contrast_ratio(p.selected_fg(), p.panel);
@@ -34,6 +35,7 @@ fn selected_row_ink_stays_readable_on_the_panel_it_is_tinted_over() {
 fn ink_on_a_solid_fill_is_readable_in_both_palettes() {
     for (name, p) in [
         ("dark", MoonPalette::TERMINAL),
+        ("graphite", MoonPalette::GRAPHITE),
         ("light", MoonPalette::LIGHT),
     ] {
         for (fill_name, fill) in [("accent", p.accent), ("panel", p.panel)] {
@@ -64,6 +66,33 @@ fn dark_terminal_palette_keeps_legacy_core_values() {
     assert_eq!(p.accent, 0xFFB347);
 }
 
+/// Catches raising `tokens.rs:MoonPalette::GRAPHITE.shell` above the dark luma threshold.
+/// A light classification flips every `is_light()` consumer to the light branch at once.
+#[test]
+fn graphite_palette_remains_a_dark_palette_by_measured_shell_luma() {
+    assert!(!MoonPalette::GRAPHITE.is_light());
+}
+
+/// Catches restoring Graphite's `text_muted` to the dark palette's low-contrast value.
+/// Muted text on Graphite's shell, window, or panel must remain readable at the WCAG floor.
+#[test]
+fn graphite_text_and_muted_text_clear_the_surface_contrast_floor() {
+    let palette = MoonPalette::GRAPHITE;
+    for (ink_name, ink) in [("text", palette.text), ("text_muted", palette.text_muted)] {
+        for (surface_name, surface) in [
+            ("shell", palette.shell),
+            ("window", palette.window),
+            ("panel", palette.panel),
+        ] {
+            let ratio = contrast_ratio(ink, surface);
+            assert!(
+                ratio >= SELECTED_TEXT_CONTRAST_FLOOR,
+                "Graphite {ink_name} on {surface_name} is {ratio:.2}:1, below {SELECTED_TEXT_CONTRAST_FLOOR}:1"
+            );
+        }
+    }
+}
+
 /// Catches changing `tokens.rs:MoonPalette::LIGHT` away from the neutral-terminal design
 /// specification, which would break semantic contrast and status coloring in the light theme.
 #[test]

crates/moon-ui-components/themes/moon-graphite.toml

@@ -0,0 +1,139 @@
+mode = "Dark"
+
+[dark.palette]
+shell = 0x33373C
+shell_high = 0x3B3F45
+window = 0x33373C
+surface = 0x373B40
+panel = 0x41464C
+panel_high = 0x464B52
+chrome = 0x3B3F45
+tabbar = 0x3B3F45
+panel_head = 0x464B52
+gutter = 0x2E3236
+chart_bg = 0x373B40
+card = 0x3B3F45
+row_alt = 0x3B3F45
+head_row = 0x41464C
+border = 0x51565D
+border_soft = 0x4C5158
+border_card = 0x51565D
+border_hover = 0x646A72
+row_line = 0x4C5158
+shadow = 0x000000
+overlay = 0xFFFFFF
+on_accent = 0xFFFFFF
+text = 0xF1EEE8
+text_soft = 0xC9C5BD
+text_dim = 0xF1EEE8
+text_muted = 0xBDB9B1
+text_faint = 0xA8A49C
+table_head = 0x41464C
+table_body = 0x3B3F45
+table_selected = 0xFFB347
+table_hover = 0x4B5057
+green = 0x2FB673
+green_btn = 0x1E8C5B
+green_text = 0x2FB673
+red = 0xFA8A8C
+red_text = 0xFA8A8C
+red_soft_bd = 0xFA8A8C
+orange = 0xFF8E5A
+amber = 0xFFB347
+blue = 0x7FC9FF
+accent = 0xFFB347
+accent_fg = 0xFFCF94
+accent_tint_a = 0.14
+yellow = 0xFFD93D
+
+[dark.metrics]
+header_top_h = 32.0
+toolbar_h = 32.0
+status_h = 22.0
+dock_tab_h = 26.0
+table_header_h = 26.0
+table_row_h = 25.0
+button_radius = 4.0
+container_radius = 8.0
+hairline = 1.0
+
+[dark.scale]
+ui = 1.0
+font = 1.0
+font_delta = 0.0
+
+[dark.typography]
+font_family = "Inter"
+mono_font_family = "Geist Mono"
+font_size = 12.0
+mono_font_size = 11.0
+rem_size = 16.0
+
+[light.palette]
+shell = 0xF3F5F7
+shell_high = 0xFAFBFC
+window = 0xF7F8FA
+surface = 0xFFFFFF
+panel = 0xF8FAFC
+panel_high = 0xFFFFFF
+chrome = 0xF5F7FA
+tabbar = 0xF2F5F8
+panel_head = 0xF5F7FA
+gutter = 0xEEF2F6
+chart_bg = 0xFFFFFF
+card = 0xFFFFFF
+row_alt = 0xFCFDFE
+head_row = 0xF3F6F8
+border = 0xD5DBE1
+border_soft = 0xE1E5EA
+border_card = 0xDCE2E8
+border_hover = 0xB8C2CC
+row_line = 0xECEFF2
+shadow = 0x000000
+overlay = 0x000000
+on_accent = 0xFFFFFF
+text = 0x17202A
+text_soft = 0x4B5865
+text_dim = 0x2D3945
+text_muted = 0x768391
+text_faint = 0x98A3AE
+table_head = 0xF3F6F8
+table_body = 0xFFFFFF
+table_selected = 0x009DFF
+table_hover = 0xEEF2F6
+green = 0x178A57
+green_btn = 0x178A57
+green_text = 0x0E6E45
+red = 0xD2483F
+red_text = 0xB7352F
+red_soft_bd = 0xE1B5B0
+orange = 0xD18A2B
+amber = 0xB97824
+blue = 0x2B6F9E
+accent = 0x009DFF
+accent_fg = 0x0A3F68
+accent_tint_a = 0.08
+yellow = 0xB8860B
+
+[light.metrics]
+header_top_h = 32.0
+toolbar_h = 32.0
+status_h = 22.0
+dock_tab_h = 26.0
+table_header_h = 26.0
+table_row_h = 25.0
+button_radius = 4.0
+container_radius = 8.0
+hairline = 1.0
+
+[light.scale]
+ui = 1.0
+font = 1.0
+font_delta = 0.0
+
+[light.typography]
+font_family = "Inter"
+mono_font_family = "Geist Mono"
+font_size = 12.0
+mono_font_size = 11.0
+rem_size = 16.0

docs/PALETTE_SPEC.md

@@ -92,6 +92,36 @@ Font scaling and global UI scaling must be architecture-level capabilities, not
 per-screen hacks. Increasing UI font size should not require hunting through
 application panels.
 
+### Bundled themes
+
+Three palettes ship in the crate, each a `MoonPalette` constant in
+`moon/tokens.rs` paired with a theme file under `crates/moon-ui-components/themes/`:
+
+| theme | file | palette | colour set |
+|---|---|---|---|
+| Terminal | `moon-terminal.toml` | `MoonPalette::TERMINAL` | dark |
+| Light | `moon-light.toml` | `MoonPalette::LIGHT` | light |
+| Graphite | `moon-graphite.toml` | `MoonPalette::GRAPHITE` | dark |
+
+The constant and the file hold the same values on purpose — the constant is what
+code reads, the file is what a host installs — so a change to one is a change to
+both, and a test pins the pair.
+
+Two rules bind a new bundled palette:
+
+- **Which side it is on is MEASURED, never declared.** `MoonPalette::is_light`
+  reads the luminance of `shell`, so a palette lands on the light or dark side by
+  its own colours. That is why Graphite needs no `ThemeMode` of its own: it is a
+  dark theme with softer surfaces, and every consumer that branches on `is_light`
+  takes the dark arm with no new code. Adding a `ThemeMode` variant to carry a
+  palette is the wrong instrument.
+- **`text` and `text_muted` must reach 4.5:1 against `shell`, `window` and
+  `panel`**, measured by `contrast_ratio` (WCAG 2.x). A palette may not borrow an
+  ink from a neighbouring theme that fails this: Graphite lifts its own
+  `text_muted` precisely because the dark palette's value measures 3.03:1 on a
+  mid-tone surface. Fix legibility in the palette's own tokens, never by adding a
+  third colour table for consumers to branch on.
+
 ## Real Component Requirement
 
 A component is not considered implemented in the palette merely because:

docs/component-api-baseline.json

@@ -4293,6 +4293,10 @@
       "file": "crates/moon-ui-components/src/moon/theme.rs",
       "signature": "pub fn load_toml(path: impl AsRef<Path>) -> Result<MoonThemeConfig, MoonThemeConfigError>"
     },
+    {
+      "file": "crates/moon-ui-components/src/moon/theme.rs",
+      "signature": "pub fn moon_graphite() -> Self"
+    },
     {
       "file": "crates/moon-ui-components/src/moon/theme.rs",
       "signature": "pub fn moon_light() -> Self"
@@ -4473,6 +4477,10 @@
       "file": "crates/moon-ui-components/src/moon/toggle.rs",
       "signature": "pub struct MoonToggle"
     },
+    {
+      "file": "crates/moon-ui-components/src/moon/tokens.rs",
+      "signature": "pub const GRAPHITE: Self = Self"
+    },
     {
       "file": "crates/moon-ui-components/src/moon/tokens.rs",
       "signature": "pub const LIGHT: Self = Self"