FIX: Correct the label alignment problem on MacOS

- Adjust the color of the dividing line to be darker in dark mode.

jira: STUDIO-12982, STUDIO-12935

Change-Id: Icda8dd10dbcc470e55c8760716f5545fb784f194
(cherry picked from commit 60aa221033134dfba19830f71cd307db91119ed6)

src/slic3r/GUI/FilamentPickerDialog.hpp

@@ -49,6 +49,11 @@ private:
     wxBoxSizer* CreateButtonPanel();
     void BindEvents();
 
+    // Preview panel helper methods
+    void CreateColorBitmap(const FilamentColor& fila_color);
+    wxBoxSizer* CreateInfoSection();
+    void SetupLabelsContent(const FilamentColor& fila_color, const std::string& fila_type);
+
     // UI update methods
     void UpdatePreview(const FilamentColorCode& filament);
     void UpdateButtonStates(wxBitmapButton* selected_btn);