diff --git a/apps/photocraft/src/main.rs b/apps/photocraft/src/main.rs
index 2a83b78ce5..27e259ce70 100644
--- a/apps/photocraft/src/main.rs
+++ b/apps/photocraft/src/main.rs
@@ -76,8 +76,7 @@ mod window_frame;
 use photocraft_engine::Session;
 use photocraft_ui_egui::PhotocraftApp;
 
-/// Matches the `.desktop` file and hicolor icon name, so Wayland docks pick up the icon.
-const APP_ID: &str = "ai.storyteller.photocraft";
+use photocraft_ui_egui::os_window::APP_ID;
 
 /// Windows and Linux: no OS title bar; the app's top bar is the title bar, with its own caption
 /// buttons and edge resizing (`photocraft_ui_egui::titlebar`), as Photoshop does on Windows. macOS
@@ -646,7 +645,14 @@ fn main() -> eframe::Result {
             // Caps Lock state (X11/Windows/macOS; `None` on native Wayland): the canvas shows the
             // precise crosshair for painting tools while it is toggled on (#1758).
             app.services.caps_lock = caps_lock::service(cc);
-            app.services.screen_pick = screen_color::service(cc, app.services.is_wayland);
+            // Pick through the portal on a Wayland desktop even when the window went through
+            // Xwayland (a pen, or the X11 display-server preference): Xwayland's root window has
+            // no desktop pixels to read (#8977).
+            #[cfg(target_os = "linux")]
+            let portal = screen_color::uses_portal(native_session);
+            #[cfg(not(target_os = "linux"))]
+            let portal = false;
+            app.services.screen_pick = screen_color::service(cc, portal);
             // Tablet pressure/tilt/eraser (winit drops them): the macOS monitor and the X11 reader
             // write into the stylus feed. The monitor goes in here, not before the event loop:
             // AppKit's shared application only exists once winit created it (#759).
diff --git a/apps/photocraft/src/screen_color.rs b/apps/photocraft/src/screen_color.rs
index ec8cd6378c..6a5ae643c5 100644
--- a/apps/photocraft/src/screen_color.rs
+++ b/apps/photocraft/src/screen_color.rs
@@ -38,6 +38,12 @@ pub fn service(cc: &eframe::CreationContext<'_>, wayland: bool) -> Option<Servic
         Pending { receiver: rx, cancelled }
     }))
 }
+/// Whether to pick through the desktop portal: on a Wayland desktop, whichever display server the
+/// window opened on. Xwayland serves only its own windows, so reading its root window fails (#8977).
+#[cfg(target_os = "linux")]
+pub fn uses_portal(desktop: crate::linux_libs::DisplaySession) -> bool {
+    desktop == crate::linux_libs::DisplaySession::Wayland
+}
 #[derive(Clone, Copy)]
 #[cfg_attr(not(any(target_os = "linux", target_os = "macos", target_os = "windows", test)), allow(dead_code))]
 struct Placement {
@@ -480,6 +486,15 @@ mod tests {
         let offset = (y * first.width + x) * 4;
         assert_eq!(&first.rgba[offset..offset + 4], &[255, 128, 64, 255]);
     }
+    #[cfg(target_os = "linux")]
+    #[test]
+    fn a_wayland_desktop_picks_through_the_portal_even_with_an_xwayland_window() {
+        use crate::linux_libs::DisplaySession;
+        // A pen or the X11 display-server preference opens the window through Xwayland, but the
+        // session is still Wayland: the X11 grab fails there with BadMatch (#8977).
+        assert!(uses_portal(DisplaySession::Wayland));
+        assert!(!uses_portal(DisplaySession::X11));
+    }
     #[test]
     fn screen_capture_matches_negative_and_hidpi_monitor_geometry() {
         let m = [Placement { index: 2, x: -3840, y: 0, width: 3840, height: 2160 }];
diff --git a/crates/ui-egui/src/canvas/tabs.rs b/crates/ui-egui/src/canvas/tabs.rs
index d3aa28546a..2ab777b532 100644
--- a/crates/ui-egui/src/canvas/tabs.rs
+++ b/crates/ui-egui/src/canvas/tabs.rs
@@ -730,7 +730,7 @@ pub fn extra_windows(app: &mut PhotocraftApp, ctx: &egui::Context) {
         let Some(st) = app.session.documents().get(w.document) else { continue };
         let title = format!("{} — window {}", st.doc.name, w.id);
         let vid = egui::ViewportId::from_hash_of(("docwin", w.id));
-        let mut builder = egui::ViewportBuilder::default().with_title(title).with_inner_size([800.0, 600.0]);
+        let mut builder = crate::os_window::builder().with_title(title).with_inner_size([800.0, 600.0]);
         if let Some([x, y]) = w.position {
             builder = builder.with_position([x, y]);
         }
diff --git a/crates/ui-egui/src/dialogs/camera_raw_ui/controls.rs b/crates/ui-egui/src/dialogs/camera_raw_ui/controls.rs
index 389af64d96..426872e347 100644
--- a/crates/ui-egui/src/dialogs/camera_raw_ui/controls.rs
+++ b/crates/ui-egui/src/dialogs/camera_raw_ui/controls.rs
@@ -210,7 +210,7 @@ pub fn show(app: &mut PhotocraftApp, ctx: &egui::Context) {
         ui.painter().rect_filled(r, 0.0, Tokens::get(ui.ctx()).scrim);
     });
     // A window of its own (title bar, moved and resized like any window), like Adobe Camera Raw.
-    let builder = egui::ViewportBuilder::default().with_title(window_title).with_inner_size([1360.0, 900.0]).with_min_inner_size([900.0, 600.0]);
+    let builder = crate::os_window::builder().with_title(window_title).with_inner_size([1360.0, 900.0]).with_min_inner_size([900.0, 600.0]);
     let mut close = false;
     ctx.show_viewport_immediate(egui::ViewportId::from_hash_of("camera-raw-window"), builder, |ui, class| {
         if ui.ctx().input(|i| i.viewport().close_requested()) {
diff --git a/crates/ui-egui/src/dialogs/screen_picker.rs b/crates/ui-egui/src/dialogs/screen_picker.rs
index 59e36636e6..25c948a6c7 100644
--- a/crates/ui-egui/src/dialogs/screen_picker.rs
+++ b/crates/ui-egui/src/dialogs/screen_picker.rs
@@ -261,7 +261,7 @@ pub fn cancel(ctx: &Context) {
 
 /// The picker window: hidden until its snapshot has been painted (#3210).
 fn viewport_builder(ctx: &Context, image: &ScreenImage) -> egui::ViewportBuilder {
-    let mut builder = egui::ViewportBuilder::default()
+    let mut builder = crate::os_window::builder()
         .with_title(tl!("PhotoCraft — Screen Color Picker"))
         .with_decorations(false)
         .with_resizable(false)
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index 4c6309e254..7c7ef766d2 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -41,6 +41,7 @@ pub mod menu_catalog;
 pub mod menus;
 pub mod monitor_status;
 pub mod notices;
+pub mod os_window;
 pub mod panels;
 pub mod preset_files_ui;
 pub mod proxy;
diff --git a/crates/ui-egui/src/os_window.rs b/crates/ui-egui/src/os_window.rs
new file mode 100644
index 0000000000..4fa88f65e3
--- /dev/null
+++ b/crates/ui-egui/src/os_window.rs
@@ -0,0 +1,19 @@
+//! Extra OS windows (document windows, Camera Raw, the screen color picker) share the main
+//! window's app id, so docks show the PhotoCraft icon on them and Wayland compositors' window
+//! rules can match them (Hyprland's `class:`, #6697). Without one their app id is empty.
+
+/// Matches the `.desktop` file and hicolor icon name, so Wayland docks pick up the icon.
+pub const APP_ID: &str = "ai.storyteller.photocraft";
+
+/// A builder for an extra OS window, carrying [`APP_ID`].
+pub fn builder() -> egui::ViewportBuilder {
+    egui::ViewportBuilder::default().with_app_id(APP_ID)
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn extra_windows_carry_the_app_id() {
+        assert_eq!(super::builder().app_id.as_deref(), Some("ai.storyteller.photocraft"));
+    }
+}