Add 7-color ACeP color scheme (Bwgbryo) + Inkplate 6COLOR palette

packages/python/src/epaper_dithering/__init__.py

@@ -11,6 +11,7 @@
     BWRY_4_2,
     HANSHOW_BWR,
     HANSHOW_BWY,
+    INKPLATE_6COLOR,
     MONO_4_26,
     SOLUM_BWR,
     SPECTRA_7_3_6COLOR,
@@ -35,4 +36,5 @@
     "SOLUM_BWR",
     "HANSHOW_BWR",
     "HANSHOW_BWY",
+    "INKPLATE_6COLOR",
 ]

packages/python/src/epaper_dithering/palettes.py

@@ -92,6 +92,24 @@ class ColorScheme(Enum):
         ),
     )
 
+    # 7-color ACeP (e.g. Inkplate 6COLOR). Color order = panel native nibbles:
+    # black0 white1 green2 blue3 red4 yellow5 orange6.
+    BWGBRYO = (
+        8,
+        ColorPalette(
+            colors={
+                "black": (0, 0, 0),
+                "white": (255, 255, 255),
+                "green": (0, 255, 0),
+                "blue": (0, 0, 255),
+                "red": (255, 0, 0),
+                "yellow": (255, 255, 0),
+                "orange": (255, 128, 0),
+            },
+            accent="red",
+        ),
+    )
+
     GRAYSCALE_4 = (
         5,
         ColorPalette(
@@ -223,3 +241,4 @@ def _load_measured_palettes() -> dict[str, "ColorPalette"]:
 SOLUM_BWR: ColorPalette = _MEASURED["SOLUM_BWR"]
 HANSHOW_BWR: ColorPalette = _MEASURED["HANSHOW_BWR"]
 HANSHOW_BWY: ColorPalette = _MEASURED["HANSHOW_BWY"]
+INKPLATE_6COLOR: ColorPalette = _MEASURED["INKPLATE_6COLOR"]

packages/rust/core/src/measured_palettes.rs

@@ -35,6 +35,12 @@ pub static CATALOG: &[MeasuredPaletteEntry] = &[
         scheme: ColorScheme::Bwgbry,
         color_names: &["black", "white", "yellow", "red", "blue", "green"],
     },
+    MeasuredPaletteEntry {
+        id: "INKPLATE_6COLOR",
+        palette: &INKPLATE_6COLOR,
+        scheme: ColorScheme::Bwgbryo,
+        color_names: &["black", "white", "green", "blue", "red", "yellow", "orange"],
+    },
     MeasuredPaletteEntry {
         id: "MONO_4_26",
         palette: &MONO_4_26,
@@ -103,6 +109,30 @@ pub static SPECTRA_7_3_6COLOR_V2: Palette = Palette {
     accent_idx: 3, // red
 };
 
+// ── Inkplate 6COLOR 7-color ACeP ─────────────────────────────────────────────
+
+/// Inkplate 6COLOR (600x448 7-color ACeP, EP585C / panel_ic_type 0x0043).
+/// Color order = panel native nibbles: black0 white1 green2 blue3 red4 yellow5 orange6.
+/// Hue-representative values tuned 2026-06-18 so source colors select the correct ink
+/// (these drive matching only; the panel always renders its own ink for each nibble).
+/// Derived from a forced-nibble calibration capture, then de-washed: the panel's raw
+/// inks photograph very desaturated (esp. green, contaminated by ghosting), which makes
+/// nearest-color matching send vivid greens->yellow and blues->black. Boosting saturation
+/// toward each ink's true hue fixes ink selection. TODO: precise per-ink measurement on a
+/// ghosting-cleared panel for tone-accurate values.
+pub static INKPLATE_6COLOR: Palette = Palette {
+    colors: Cow::Borrowed(&[
+        [ 45,  45,  70],  // black (dark blue-gray)
+        [230, 230, 230],  // white
+        [ 60, 150,  80],  // green
+        [ 40,  70, 190],  // blue
+        [200,  40,  40],  // red
+        [235, 215,  90],  // yellow
+        [225, 120,  40],  // orange
+    ]),
+    accent_idx: 4, // red
+};
+
 // ── Monochrome displays ───────────────────────────────────────────────────────
 
 /// 4.26" Monochrome. TODO: measure actual display.

packages/rust/core/src/palettes.rs

@@ -49,6 +49,9 @@ pub enum ColorScheme {
     Grayscale16 = 6,
     /// Reserved: 8-level grayscale, pending firmware value assignment.
     Grayscale8 = 7,
+    /// 7-color ACeP (e.g. Inkplate 6COLOR). Color order matches the panel's
+    /// native nibble codes: black0 white1 green2 blue3 red4 yellow5 orange6.
+    Bwgbryo    = 8,
 }
 
 // ── Palette data ─────────────────────────────────────────────────────────────
@@ -76,6 +79,14 @@ static PALETTE_BWGBRY: Palette = Palette {
     ]),
     accent_idx: 3,
 };
+// 7-color ACeP. Order = panel native nibbles: black0 white1 green2 blue3 red4 yellow5 orange6.
+static PALETTE_BWGBRYO: Palette = Palette {
+    colors: Cow::Borrowed(&[
+        [0, 0, 0], [255, 255, 255], [0, 255, 0], [0, 0, 255],
+        [255, 0, 0], [255, 255, 0], [255, 128, 0],
+    ]),
+    accent_idx: 4, // red
+};
 static PALETTE_GRAYSCALE4: Palette = Palette {
     colors: Cow::Borrowed(&[[0, 0, 0], [85, 85, 85], [170, 170, 170], [255, 255, 255]]),
     accent_idx: 0,
@@ -110,6 +121,7 @@ impl ColorScheme {
             ColorScheme::Grayscale4  => &PALETTE_GRAYSCALE4,
             ColorScheme::Grayscale16 => &PALETTE_GRAYSCALE16,
             ColorScheme::Grayscale8  => &PALETTE_GRAYSCALE8,
+            ColorScheme::Bwgbryo     => &PALETTE_BWGBRYO,
         }
     }
 }
@@ -135,6 +147,7 @@ impl TryFrom<u8> for ColorScheme {
             5 => Ok(ColorScheme::Grayscale4),
             6 => Ok(ColorScheme::Grayscale16),
             7 => Ok(ColorScheme::Grayscale8),
+            8 => Ok(ColorScheme::Bwgbryo),
             _ => Err(DitherError::UnknownColorScheme(v)),
         }
     }
@@ -171,5 +184,27 @@ mod tests {
         assert_eq!(ColorScheme::Mono.palette().colors.len(), 2);
         assert_eq!(ColorScheme::Bwgbry.palette().colors.len(), 6);
         assert_eq!(ColorScheme::Grayscale16.palette().colors.len(), 16);
+        assert_eq!(ColorScheme::Bwgbryo.palette().colors.len(), 7);
+    }
+
+    #[test]
+    fn bwgbryo_is_value_8() {
+        assert_eq!(u8::from(ColorScheme::Bwgbryo), 8);
+        assert_eq!(ColorScheme::try_from(8), Ok(ColorScheme::Bwgbryo));
+    }
+
+    #[test]
+    fn bwgbryo_order_matches_panel_native_nibbles() {
+        // The dither output index is the 4bpp nibble sent to the panel, so the
+        // palette order MUST match the Inkplate 6COLOR's native codes:
+        // black0 white1 green2 blue3 red4 yellow5 orange6.
+        let c = &ColorScheme::Bwgbryo.palette().colors;
+        assert_eq!(c[0], [0, 0, 0], "idx0 black");
+        assert_eq!(c[1], [255, 255, 255], "idx1 white");
+        assert_eq!(c[2], [0, 255, 0], "idx2 green");
+        assert_eq!(c[3], [0, 0, 255], "idx3 blue");
+        assert_eq!(c[4], [255, 0, 0], "idx4 red");
+        assert_eq!(c[5], [255, 255, 0], "idx5 yellow");
+        assert_eq!(c[6], [255, 128, 0], "idx6 orange");
     }
 }