diff --git a/src/app/dock/tests.rs b/src/app/dock/tests.rs
index eeda37b0e..b8858fa2c 100644
--- a/src/app/dock/tests.rs
+++ b/src/app/dock/tests.rs
@@ -393,6 +393,30 @@ fn dock_hover_reveals_groups_only_on_an_auto_hiding_edge() {
     assert!(app.dock_edge_expanded(DockSide::Left));
 }
 
+#[test]
+fn dock_auto_hide_waits_for_an_open_layer_color_dropdown() {
+    use crate::ui::dock::{DockGroup, DockMsg, PanelId};
+    let mut app = dock_app();
+    app.dock.left.push(DockGroup::single(PanelId::Layers));
+    let _ = app.on_dock(DockMsg::AutoCollapseToggle(PanelId::Layers));
+    let _ = app.on_dock(DockMsg::Hover(PanelId::Layers));
+    let _ = app.on_dock(DockMsg::HoverSettled(app.dock_hover_gen));
+    assert_eq!(app.dock_peek, Some(PanelId::Layers));
+    // Opening a row's colour swatch, then moving onto its dropdown, reads
+    // as the pointer leaving the edge: the panel must stay out.
+    let _ = app.update(Message::LayerColorPickerToggle("0".to_string()));
+    assert!(app.tabs[app.active_tab].layers.color_picker_row.is_some());
+    let _ = app.on_dock(DockMsg::HoverExit);
+    let _ = app.on_dock(DockMsg::HoverSettled(app.dock_hover_gen));
+    assert_eq!(app.dock_peek, Some(PanelId::Layers));
+    let _ = app.on_dock(DockMsg::HoverSettled(app.dock_hover_gen));
+    assert_eq!(app.dock_peek, Some(PanelId::Layers));
+    // Once the dropdown closes with the pointer still away, it hides.
+    let _ = app.update(Message::LayerColorPickerToggle("0".to_string()));
+    let _ = app.on_dock(DockMsg::HoverSettled(app.dock_hover_gen));
+    assert_eq!(app.dock_peek, None);
+}
+
 #[test]
 fn dock_float_resize_grows_the_panel() {
     use crate::ui::dock::{DockMsg, FloatPanel, PanelId};
@@ -558,6 +582,141 @@ fn drive_view(app: &mut OpenCADStudio, at: iced::Point, events: &[iced::Event])
     }
 }
 
+/// The hover messages an open dropdown inside a hover zone (`zone`) or a
+/// `mouse_area` publishes as the pointer goes from the field onto the
+/// dropdown's list, then out of the area, each tagged with where the pointer
+/// was.
+fn hover_messages_over_an_open_dropdown(zone: bool) -> Vec<(&'static str, &'static str)> {
+    use crate::ui::dock::DockMsg;
+    use iced::widget::{button, column, container, mouse_area, text};
+    use iced_test::core::{mouse, shell, window};
+    use iced_test::runtime::user_interface::{Cache, UserInterface};
+    let view = || -> iced::Element<'static, Message> {
+        let field = button(text("ByLayer")).width(120).height(20);
+        // A pointer-wanting list, like a linetype combo's, under the field.
+        let list = button(column![text("Continuous"), text("Dashed")])
+            .on_press(Message::Dock(DockMsg::HoverEnd(
+                crate::ui::dock::PanelId::Layers,
+            )))
+            .width(120)
+            .height(100);
+        let dd = iced_aw::DropDown::new(field, list, true)
+            .alignment(iced_aw::drop_down::Alignment::Bottom);
+        let area = container(dd).width(300).height(400);
+        let (enter, exit) = (
+            Message::Dock(DockMsg::HoverStay),
+            Message::Dock(DockMsg::HoverExit),
+        );
+        if zone {
+            crate::ui::hover_zone::hover_zone(area, enter, exit)
+        } else {
+            mouse_area(area).on_enter(enter).on_exit(exit).into()
+        }
+    };
+    let mut renderer = headless_renderer();
+    let mut cache = Cache::default();
+    let mut seen = Vec::new();
+    // On the field, on the open list (both inside the area), then outside.
+    for (place, x, y) in [
+        ("field", 60.0, 10.0),
+        ("list", 60.0, 70.0),
+        ("list", 60.0, 90.0),
+        ("outside", 500.0, 70.0),
+    ] {
+        let at = iced::Point::new(x, y);
+        let mut messages = Vec::new();
+        let mut ui = UserInterface::build(view(), VIEW_SIZE, cache, &mut renderer);
+        let _ = ui.update(
+            &window::Headless,
+            &shell::Waker::noop(),
+            &[iced::Event::Mouse(mouse::Event::CursorMoved {
+                position: at,
+            })],
+            mouse::Cursor::Available(at),
+            &mut renderer,
+            &mut messages,
+        );
+        cache = ui.into_cache();
+        seen.extend(messages.into_iter().filter_map(|m| match m {
+            Message::Dock(DockMsg::HoverStay) => Some(("enter", place)),
+            Message::Dock(DockMsg::HoverExit) => Some(("exit", place)),
+            _ => None,
+        }));
+    }
+    seen
+}
+
+#[test]
+fn an_open_dropdown_in_a_hover_zone_does_not_read_as_leaving() {
+    with_stack(|| {
+        // The bug: a mouse area reads the pointer on the list as gone.
+        assert_eq!(
+            hover_messages_over_an_open_dropdown(false),
+            [("enter", "field"), ("exit", "list")]
+        );
+        assert_eq!(
+            hover_messages_over_an_open_dropdown(true),
+            [("enter", "field"), ("exit", "outside")]
+        );
+    });
+}
+
+/// Bounds of the field (text `ByLayer`) and of its open list (text `Opaque`)
+/// for a `drop_down_below` in a scrollable that, like a pallet, sits away
+/// from the window's top-left corner.
+fn drop_down_below_in_an_offset_scrollable() -> (iced::Rectangle, iced::Rectangle) {
+    use iced::widget::{button, column, container, row, scrollable, text, Space};
+    use iced_test::core::widget;
+    use iced_test::runtime::user_interface::{Cache, UserInterface};
+    use iced_test::Selector;
+    let view = || -> iced::Element<'static, Message> {
+        let field = container(text("ByLayer")).width(200).height(20);
+        let list = column![
+            button(text("Opaque")).width(iced::Fill),
+            button(text("50")).width(iced::Fill),
+        ];
+        let dd = crate::ui::color_select::drop_down_below(
+            field.into(),
+            list.into(),
+            None,
+            iced::Length::Shrink,
+            Message::PropEditChoiceToggle,
+        );
+        let pallet = scrollable(column![Space::new().height(300), dd]).height(500);
+        row![
+            Space::new().width(1000),
+            container(pallet).width(300).height(iced::Fill)
+        ]
+        .into()
+    };
+    let mut renderer = headless_renderer();
+    let mut ui = UserInterface::build(view(), VIEW_SIZE, Cache::default(), &mut renderer);
+    let mut find = |label: &str| {
+        let mut find = Selector::find(label);
+        ui.operate(&renderer, &mut widget::operation::black_box(&mut find));
+        match widget::Operation::finish(&find) {
+            widget::operation::Outcome::Some(Some(target)) => target.bounds(),
+            _ => panic!("{label} not found"),
+        }
+    };
+    (find("ByLayer"), find("Opaque"))
+}
+
+#[test]
+fn a_drop_down_in_a_pallet_opens_right_below_its_field() {
+    with_stack(|| {
+        let (field, item) = drop_down_below_in_an_offset_scrollable();
+        assert!(
+            item.y >= field.y + field.height && item.y < field.y + field.height + 20.0,
+            "list starts below the field: field {field:?}, first item {item:?}"
+        );
+        assert!(
+            item.x >= field.x - 1.0 && item.x < field.x + field.width,
+            "list lines up with the field: field {field:?}, first item {item:?}"
+        );
+    });
+}
+
 #[test]
 fn docked_title_bar_double_click_floats_the_pallet_in_the_real_view() {
     // Building the real view is deeper than a default test thread's stack.
diff --git a/src/app/dock/update.rs b/src/app/dock/update.rs
index e77857c45..bbbf46ff5 100644
--- a/src/app/dock/update.rs
+++ b/src/app/dock/update.rs
@@ -207,6 +207,15 @@ impl OpenCADStudio {
                         Some(HoverPending::Hide)
                             if self.dock_peek.is_some_and(|id| self.dock.auto_hides(id)) =>
                         {
+                            // The edge's hover zone keeps a dropdown inside
+                            // it from reading as a leave; a colour popup can
+                            // still reach past it (or be the Select Color
+                            // window). Keep the panel out until it closes, so
+                            // a pick can still land; then hide unless the
+                            // pointer is back (its re-entry cancels this).
+                            if self.dock_popup_open() {
+                                return self.dock_hover_arm(HoverPending::Hide);
+                            }
                             self.dock_peek = None;
                         }
                         _ => {}
@@ -412,6 +421,17 @@ impl OpenCADStudio {
         })
     }
 
+    /// Whether a popup a pallet opened is showing: a colour dropdown in the
+    /// Layer Manager or Properties, or the Select Color window.
+    fn dock_popup_open(&self) -> bool {
+        let tab = &self.tabs[self.active_tab];
+        tab.layers.color_picker_row.is_some()
+            || tab.properties.color_picker_open
+            || tab.properties.bg_color_picker_open
+            || tab.properties.open_color_field.is_some()
+            || self.color_picker.is_some()
+    }
+
     /// Drop any pending delayed reveal / hide.
     fn dock_hover_cancel(&mut self) {
         self.dock_hover_gen = self.dock_hover_gen.wrapping_add(1);
diff --git a/src/app/dock/view.rs b/src/app/dock/view.rs
index a1735fd93..2bb0e5e5f 100644
--- a/src/app/dock/view.rs
+++ b/src/app/dock/view.rs
@@ -164,12 +164,13 @@ impl OpenCADStudio {
                 children.push(strip);
             }
         }
-        Some(
-            mouse_area(row(children).height(Fill))
-                .on_enter(Message::Dock(crate::ui::dock::DockMsg::HoverStay))
-                .on_exit(Message::Dock(crate::ui::dock::DockMsg::HoverExit))
-                .into(),
-        )
+        // Not a `mouse_area`: the pointer on one of the pallet's own
+        // dropdowns must not read as leaving the edge.
+        Some(crate::ui::hover_zone::hover_zone(
+            row(children).height(Fill),
+            Message::Dock(crate::ui::dock::DockMsg::HoverStay),
+            Message::Dock(crate::ui::dock::DockMsg::HoverExit),
+        ))
     }
 
     /// An edge's vertical icon strip: per group its open pallets' icons in a
@@ -555,10 +556,14 @@ impl OpenCADStudio {
         // on its empty areas don't fall through to the drawing below.
         let panel = mouse_area(framed)
             .on_press(Message::Dock(DockMsg::FloatRaise(f.id)))
-            .on_enter(Message::Dock(DockMsg::Hover(f.id)))
-            .on_exit(Message::Dock(DockMsg::HoverExit))
             .interaction(iced::mouse::Interaction::Idle);
-        place_at(panel.into(), x, y)
+        // Enter / leave as on a docked edge: its dropdowns keep it shown.
+        let panel = crate::ui::hover_zone::hover_zone(
+            panel,
+            Message::Dock(DockMsg::Hover(f.id)),
+            Message::Dock(DockMsg::HoverExit),
+        );
+        place_at(panel, x, y)
     }
 
     /// Where floating panel `f` draws.
diff --git a/src/ui/color_select/mod.rs b/src/ui/color_select/mod.rs
index 445a52bbc..2eb812bf8 100644
--- a/src/ui/color_select/mod.rs
+++ b/src/ui/color_select/mod.rs
@@ -322,5 +322,5 @@ pub fn drop_down_below<'a>(
     if let Some(w) = popup_width {
         dd = dd.width(w);
     }
-    dd.into()
+    crate::ui::drop_down_fit::drop_down_fit(dd)
 }
diff --git a/src/ui/drop_down_fit.rs b/src/ui/drop_down_fit.rs
new file mode 100644
index 000000000..127ef93e1
--- /dev/null
+++ b/src/ui/drop_down_fit.rs
@@ -0,0 +1,131 @@
+//! Keeps an `iced_aw::DropDown` list under its field inside a scrollable.
+//!
+//! The drop-down keeps its list on screen by testing it against the viewport
+//! it is handed, but reads only that viewport's width and height, as if it
+//! started at the window's top-left corner. Inside a scrollable the viewport
+//! is the scrollable's visible area in window coordinates, so a field in a
+//! dock pallet (which does not start at the corner) sees its list "overflow",
+//! and the list jumps left by its own width or up over the field. Wrapped
+//! here, the drop-down gets a viewport reaching from the window corner to the
+//! visible area's far edges: the test then trips only where the list really
+//! leaves the visible area.
+
+use iced::advanced::layout::{self, Layout};
+use iced::advanced::widget::{self, tree, Tree, Widget};
+use iced::advanced::{mouse, overlay, renderer, Shell};
+use iced::{Element, Event, Length, Rectangle, Renderer, Size, Theme, Vector};
+
+use crate::app::Message;
+
+/// Wrap a drop-down so its list is placed against the visible area's real
+/// edges.
+pub fn drop_down_fit<'a>(drop_down: impl Into<Element<'a, Message>>) -> Element<'a, Message> {
+    Element::new(DropDownFit {
+        content: drop_down.into(),
+    })
+}
+
+struct DropDownFit<'a> {
+    content: Element<'a, Message>,
+}
+
+impl Widget<Message, Theme, Renderer> for DropDownFit<'_> {
+    fn tag(&self) -> tree::Tag {
+        self.content.as_widget().tag()
+    }
+
+    fn state(&self) -> tree::State {
+        self.content.as_widget().state()
+    }
+
+    fn diff(&mut self, tree: &mut Tree) {
+        self.content.as_widget_mut().diff(tree);
+    }
+
+    fn size(&self) -> Size<Length> {
+        self.content.as_widget().size()
+    }
+
+    fn layout(
+        &mut self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        self.content.as_widget_mut().layout(tree, renderer, limits)
+    }
+
+    fn operate(
+        &mut self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn widget::Operation,
+    ) {
+        self.content
+            .as_widget_mut()
+            .operate(tree, layout, renderer, operation);
+    }
+
+    fn update(
+        &mut self,
+        tree: &mut Tree,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) {
+        self.content
+            .as_widget_mut()
+            .update(tree, event, layout, cursor, renderer, shell, viewport);
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content
+            .as_widget()
+            .mouse_interaction(tree, layout, cursor, viewport, renderer)
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        self.content
+            .as_widget()
+            .draw(tree, renderer, theme, style, layout, cursor, viewport);
+    }
+
+    fn overlay<'b>(
+        &'b mut self,
+        tree: &'b mut Tree,
+        layout: Layout<'b>,
+        renderer: &Renderer,
+        viewport: &Rectangle,
+        translation: Vector,
+    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
+        let from_corner = Rectangle {
+            x: 0.0,
+            y: 0.0,
+            width: viewport.x + viewport.width,
+            height: viewport.y + viewport.height,
+        };
+        self.content
+            .as_widget_mut()
+            .overlay(tree, layout, renderer, &from_corner, translation)
+    }
+}
diff --git a/src/ui/hover_zone.rs b/src/ui/hover_zone.rs
new file mode 100644
index 000000000..c9269194e
--- /dev/null
+++ b/src/ui/hover_zone.rs
@@ -0,0 +1,175 @@
+//! A pointer-enter / leave area that keeps counting the pointer as inside
+//! while it rests on an overlay (a dropdown, a combo box list) drawn over
+//! its bounds.
+//!
+//! `mouse_area` reads such a pointer as gone: iced hands the layer below an
+//! overlay that wants the pointer an unavailable cursor, with no position. An
+//! auto-hiding dock edge then hid as soon as one of its own dropdowns opened
+//! under the pointer, taking the dropdown with it. Here an unavailable cursor
+//! keeps the last state, so only a pointer seen outside the bounds, or one
+//! that leaves the window, exits the area.
+
+use iced::advanced::layout::{self, Layout};
+use iced::advanced::widget::{self, tree, Tree, Widget};
+use iced::advanced::{mouse, overlay, renderer, Shell};
+use iced::{Element, Event, Length, Rectangle, Renderer, Size, Theme, Vector};
+
+use crate::app::Message;
+
+/// Wrap `content`, publishing `on_enter` / `on_exit` as the pointer enters
+/// and leaves its bounds, overlays drawn over them included.
+pub fn hover_zone<'a>(
+    content: impl Into<Element<'a, Message>>,
+    on_enter: Message,
+    on_exit: Message,
+) -> Element<'a, Message> {
+    Element::new(HoverZone {
+        content: content.into(),
+        on_enter,
+        on_exit,
+    })
+}
+
+struct HoverZone<'a> {
+    content: Element<'a, Message>,
+    on_enter: Message,
+    on_exit: Message,
+}
+
+#[derive(Default)]
+struct State {
+    hovered: bool,
+}
+
+impl Widget<Message, Theme, Renderer> for HoverZone<'_> {
+    fn tag(&self) -> tree::Tag {
+        tree::Tag::of::<State>()
+    }
+
+    fn state(&self) -> tree::State {
+        tree::State::new(State::default())
+    }
+
+    fn diff(&mut self, tree: &mut Tree) {
+        tree.diff_children(std::slice::from_mut(&mut self.content));
+    }
+
+    fn size(&self) -> Size<Length> {
+        self.content.as_widget().size()
+    }
+
+    fn layout(
+        &mut self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        self.content
+            .as_widget_mut()
+            .layout(&mut tree.children[0], renderer, limits)
+    }
+
+    fn operate(
+        &mut self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn widget::Operation,
+    ) {
+        self.content
+            .as_widget_mut()
+            .operate(&mut tree.children[0], layout, renderer, operation);
+    }
+
+    fn update(
+        &mut self,
+        tree: &mut Tree,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget_mut().update(
+            &mut tree.children[0],
+            event,
+            layout,
+            cursor,
+            renderer,
+            shell,
+            viewport,
+        );
+        // Unlike `mouse_area`, this runs for captured events too, and a
+        // cursor without a position (on an overlay) changes nothing.
+        let hovered = match (event, cursor.land()) {
+            (Event::Mouse(mouse::Event::CursorLeft), _) => false,
+            (_, mouse::Cursor::Available(p)) => layout.bounds().contains(p),
+            _ => return,
+        };
+        let state = tree.state.downcast_mut::<State>();
+        if hovered != state.hovered {
+            state.hovered = hovered;
+            shell.publish(if hovered {
+                self.on_enter.clone()
+            } else {
+                self.on_exit.clone()
+            });
+        }
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout,
+            cursor,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            theme,
+            style,
+            layout,
+            cursor,
+            viewport,
+        );
+    }
+
+    fn overlay<'b>(
+        &'b mut self,
+        tree: &'b mut Tree,
+        layout: Layout<'b>,
+        renderer: &Renderer,
+        viewport: &Rectangle,
+        translation: Vector,
+    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
+        self.content.as_widget_mut().overlay(
+            &mut tree.children[0],
+            layout,
+            renderer,
+            viewport,
+            translation,
+        )
+    }
+}
diff --git a/src/ui/mod.rs b/src/ui/mod.rs
index 4b7608424..c894b3abf 100644
--- a/src/ui/mod.rs
+++ b/src/ui/mod.rs
@@ -5,6 +5,8 @@ pub const ROW_H: f32 = 26.0;
 pub mod color_select;
 pub mod command_line;
 pub mod dock;
+pub mod drop_down_fit;
+pub mod hover_zone;
 pub mod icons;
 pub mod menu_bar;
 pub mod modal;