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))