diff --git a/sources/diagramview.cpp b/sources/diagramview.cpp
index 9e89be6cb..a0e662306 100644
--- a/sources/diagramview.cpp
+++ b/sources/diagramview.cpp
@@ -40,6 +40,7 @@
 #include "NameList/nameslist.h"
 #include "elementdialog.h"
 #include <QDropEvent>
+#include <QPointer>
 
 /**
 	Constructeur
@@ -122,7 +123,7 @@ DiagramView::DiagramView(Diagram *diagram, QWidget *parent) :
 		ConductorProperties initial_properties = edited_conductor->properties();
 
 			// prepare a color dialog showing the initial conductor color
-		QColorDialog *color_dialog = new QColorDialog(this);
+		QPointer<QColorDialog> color_dialog = new QColorDialog(this);
 		color_dialog->setWindowTitle(tr("Choisir la nouvelle couleur de ce conducteur"));
 #ifdef Q_OS_MACOS
 		color_dialog -> setWindowFlags(Qt::Sheet);
@@ -150,6 +151,8 @@ DiagramView::DiagramView(Diagram *diagram, QWidget *parent) :
 				LastUsedStyle::setConductorColor(new_color);
 			}
 		}
+		if (color_dialog)
+			delete color_dialog;
 	});
 }
 
diff --git a/sources/qet.cpp b/sources/qet.cpp
index bf4415e94..f253fc114 100644
--- a/sources/qet.cpp
+++ b/sources/qet.cpp
@@ -20,10 +20,13 @@
 #include "shortcutmanager.h"
 
 #include <limits>
+#include <QBuffer>
+#include <QColorDialog>
 #include <QGraphicsSceneContextMenuEvent>
 #include <QAction>
 #include <QFileInfo>
 #include <QSaveFile>
+#include <QSettings>
 #include <QTextStream>
 #include <QRegularExpression>
 #include <QActionGroup>
@@ -845,3 +848,55 @@ bool QET::writeToFile(QDomDocument &xml_doc, QFile *file, QString *error_message
 
 	return(true);
 }
+
+/**
+	@brief QET::saveCustomColors
+	Save the 16 QColorDialog custom colors to QSettings so they persist
+	across application restarts.
+*/
+void QET::saveCustomColors()
+{
+	QByteArray ba;
+	QBuffer buf(&ba);
+	buf.open(QIODevice::WriteOnly);
+	QDataStream s(&buf);
+	s.setVersion(QDataStream::Qt_6_0);
+	for (int i = 0; i < 16; i++)
+		s << QColorDialog::customColor(i);
+	QSettings settings;
+	settings.setValue(QStringLiteral("color/customColors"), ba);
+}
+
+/**
+	@brief QET::loadCustomColors
+	Load the 16 QColorDialog custom colors from QSettings into Qt's
+	internal custom color array.  A short or corrupt buffer is ignored
+	so that unread slots keep their default rather than turning black.
+*/
+void QET::loadCustomColors()
+{
+	QSettings settings;
+	QByteArray ba = settings.value(QStringLiteral("color/customColors")).toByteArray();
+
+	// Fall back to the legacy ungrouped key used by earlier versions.
+	if (ba.isEmpty())
+		ba = settings.value(QStringLiteral("customColors")).toByteArray();
+
+	if (ba.isEmpty())
+		return;
+
+	QBuffer buf(&ba);
+	buf.open(QIODevice::ReadOnly);
+	QDataStream s(&buf);
+	s.setVersion(QDataStream::Qt_6_0);
+
+	QColor colors[16];
+	for (int i = 0; i < 16; i++)
+		s >> colors[i];
+
+	if (s.status() != QDataStream::Ok)
+		return;
+
+	for (int i = 0; i < 16; i++)
+		QColorDialog::setCustomColor(i, colors[i]);
+}
diff --git a/sources/qet.h b/sources/qet.h
index 51e951d0f..da544ac13 100644
--- a/sources/qet.h
+++ b/sources/qet.h
@@ -18,6 +18,7 @@
 #ifndef _QET_H
 #define _QET_H
 
+#include <QColor>
 #include <QDomElement>
 #include <QFile>
 #include <QObject>
@@ -185,6 +186,8 @@ namespace QET {
 	bool writeToFile (QDomDocument &xml_doc, QFile *file, QString *error_message = nullptr);
 	bool eachStrIsEqual (const QStringList &qsl);
 	QActionGroup *depthActionGroup(QObject *parent = nullptr);
+	void saveCustomColors();
+	void loadCustomColors();
 }
 
 Q_DECLARE_METATYPE(QET::DepthOption)
diff --git a/sources/qetapp.cpp b/sources/qetapp.cpp
index 0d31378d4..ed31bf0a4 100644
--- a/sources/qetapp.cpp
+++ b/sources/qetapp.cpp
@@ -18,6 +18,7 @@
 #include "qetapp.h"
 
 #include "configdialog.h"
+#include "qet.h"
 #include "ui/configpage/configpages.h"
 #include "editor/ui/qetelementeditor.h"
 #include "elementscollectioncache.h"
@@ -124,6 +125,7 @@ QETApp::QETApp() :
 	QET::Icons::initIcons();
 	initFonts();
 	initStyle();
+	QET::loadCustomColors();
 	initSplashScreen();
 	initSystemTray();
 
@@ -168,6 +170,7 @@ QETApp::QETApp() :
 */
 QETApp::~QETApp()
 {
+	QET::saveCustomColors();
 	m_elements_recent_files->save();
 	m_projects_recent_files->save();