fix(layers): preserve true colors

Closes #587

src/app/layers.rs

@@ -64,7 +64,7 @@ impl OpenCADStudio {
             .iter()
             .map(|l| crate::ui::ribbon::LayerInfo {
                 name: l.name.clone(),
-                color: l.color,
+                color: crate::ui::window::layers::iced_color_from_acad(&l.color),
                 visible: l.visible,
                 frozen: l.frozen,
                 locked: l.locked,

src/app/mod.rs

@@ -1708,7 +1708,7 @@ pub enum Message {
     LayerRenameEdit(String),
     LayerColorPickerToggle(usize),
     LayerColorMorePalette,
-    LayerColorSet(u8),
+    LayerColorSet(acadrust::types::Color),
     LayerLinetypeSet(String),
     LayerLineweightSet(LineWeight),
     LayerTransparencyEdit(usize, String),

src/app/update/mod.rs

@@ -1,7 +1,6 @@
 use super::{Message, OpenCADStudio};
 use crate::scene::VIEWCUBE_DRAW_PX;
 use crate::ui::PropertiesPanel;
-use acadrust::types::Color as AcadColor;
 use iced::time::Instant;
 use iced::Task;
 
@@ -1998,22 +1997,20 @@ impl OpenCADStudio {
                 Task::none()
             }
 
-            Message::LayerColorSet(aci) => {
+            Message::LayerColorSet(color) => {
                 let i = self.active_tab;
                 // Apply to every selected layer (multi-select), not just one.
                 let names = self.selected_layer_names(i);
                 if !names.is_empty() {
                     let undo = self.begin_layer_undo(i, "LAYER COLOR", &names);
-                    use crate::ui::window::layers::iced_color_from_acad;
-                    let new_color = iced_color_from_acad(&AcadColor::Index(aci));
                     for name in &names {
                         if let Some(dl) = self.tabs[i].scene.document.layers.get_mut(name) {
-                            dl.color = AcadColor::Index(aci);
+                            dl.color = color;
                         }
                     }
                     for pl in self.tabs[i].layers.layers.iter_mut() {
                         if names.contains(&pl.name) {
-                            pl.color = new_color;
+                            pl.color = color;
                         }
                     }
                     self.tabs[i].dirty = true;

src/app/update/style.rs

@@ -986,14 +986,7 @@ pub(super) fn on_text_style_dialog_open(&mut self) -> Task<Message> {
                     }
                     Some(crate::app::ColorPickTarget::Layer(idx)) => {
                         self.tabs[self.active_tab].layers.selected = Some(idx);
-                        let index = match color {
-                            acadrust::types::Color::Index(i) => i,
-                            acadrust::types::Color::Rgb { r, g, b } => {
-                                crate::ui::color_select::nearest_aci(r, g, b)
-                            }
-                            _ => 7,
-                        };
-                        Some(Message::LayerColorSet(index))
+                        Some(Message::LayerColorSet(color))
                     }
                     Some(crate::app::ColorPickTarget::LayerState(idx)) => {
                         Some(Message::LayerStateEditorLayerColor(idx, color))

src/ui/window/layers.rs

@@ -84,7 +84,7 @@ pub struct Layer {
     pub visible: bool,
     pub frozen: bool,
     pub locked: bool,
-    pub color: Color,
+    pub color: AcadColor,
     pub linetype: String,
     pub lineweight: LineWeight,
     pub transparency: i32,
@@ -93,7 +93,7 @@ pub struct Layer {
 }
 
 impl Layer {
-    pub fn new(name: &str, color: Color) -> Self {
+    pub fn new(name: &str, color: AcadColor) -> Self {
         Self {
             name: name.to_string(),
             visible: true,
@@ -143,7 +143,7 @@ impl Default for LayerPanel {
     fn default() -> Self {
         Self {
             visible: false,
-            layers: vec![Layer::new("0", Color::WHITE)],
+            layers: vec![Layer::new("0", AcadColor::Index(7))],
             selected: None,
             selected_multi: Vec::new(),
             editing: None,
@@ -212,7 +212,7 @@ impl LayerPanel {
                     visible: !l.flags.off,
                     frozen: l.flags.frozen,
                     locked: l.flags.locked,
-                    color: iced_color_from_acad(&l.color),
+                    color: l.color,
                     linetype: if l.line_type.is_empty() {
                         "Continuous".to_string()
                     } else {
@@ -526,7 +526,8 @@ fn layer_header_button_style(theme: &Theme, status: button::Status) -> button::S
 }
 
 /// Packed RGB key for ordering colours deterministically by hue-ish bytes.
-fn color_sort_key(c: Color) -> u32 {
+fn color_sort_key(c: AcadColor) -> u32 {
+    let c = iced_color_from_acad(&c);
     let q = |v: f32| (v.clamp(0.0, 1.0) * 255.0).round() as u32;
     (q(c.r) << 16) | (q(c.g) << 8) | q(c.b)
 }
@@ -763,26 +764,20 @@ fn layer_row<'a>(
     };
 
     // Color cell — looks like a combo_box input; click opens swatch dropdown below row.
-    let aci = iced_to_aci(layer.color);
-    let cur_color_name = color_label_aci(aci).to_string();
-    let _ = cur_color_name;
     // Shared colour selector. Layers carry a concrete colour (no ByLayer /
-    // ByBlock); the chosen index is applied to this row.
+    // ByBlock); true colours stay RGB instead of being collapsed to ACI 7.
     let color_cell: Element<'_, Message> = container(crate::ui::color_select::color_selector(
-        acadrust::types::Color::Index(aci),
+        layer.color,
         color_picker_open,
         crate::ui::color_select::ColorExtras {
             by_layer: false,
             by_block: false,
         },
-        |c| match c {
-            acadrust::types::Color::Index(i) => Message::LayerColorSet(i),
-            _ => Message::LayerColorSet(7),
-        },
+        Message::LayerColorSet,
         Message::LayerColorPickerToggle(index),
         Message::OpenColorWindow(
             crate::app::ColorPickTarget::Layer(index),
-            acadrust::types::Color::Index(aci),
+            layer.color,
         ),
     ))
     .width(Length::Fixed(COL_COLOR))
@@ -940,44 +935,6 @@ fn combo_input_style(
 
 // ── Display helpers ───────────────────────────────────────────────────────
 
-#[allow(dead_code)]
-fn aci_color_display(i: u8) -> (Color, &'static str) {
-    let (r, g, b) = aci_to_rgb(i).unwrap_or((200, 200, 200));
-    (
-        Color::from_rgb(r as f32 / 255.0, g as f32 / 255.0, b as f32 / 255.0),
-        "",
-    )
-}
-
-fn iced_to_aci(c: Color) -> u8 {
-    let r = (c.r * 255.0) as u8;
-    let g = (c.g * 255.0) as u8;
-    let b = (c.b * 255.0) as u8;
-    for i in 1u8..=255 {
-        if let Some((ar, ag, ab)) = aci_to_rgb(i) {
-            if ar == r && ag == g && ab == b {
-                return i;
-            }
-        }
-    }
-    7
-}
-
-fn color_label_aci(i: u8) -> &'static str {
-    match i {
-        1 => "red",
-        2 => "yellow",
-        3 => "green",
-        4 => "cyan",
-        5 => "blue",
-        6 => "magenta",
-        7 => "white",
-        8 => "dark gray",
-        9 => "gray",
-        _ => "white",
-    }
-}
-
 pub fn iced_color_from_acad(c: &AcadColor) -> Color {
     match c {
         AcadColor::Index(i) => {