diff --git a/Pdf4QtLib/sources/pdftransparencyrenderer.cpp b/Pdf4QtLib/sources/pdftransparencyrenderer.cpp
index bc532b0..609d4a6 100644
--- a/Pdf4QtLib/sources/pdftransparencyrenderer.cpp
+++ b/Pdf4QtLib/sources/pdftransparencyrenderer.cpp
@@ -74,6 +74,22 @@ PDFColorBuffer PDFFloatBitmap::getPixels()
     return PDFColorBuffer(m_data.data(), m_data.size());
 }
 
+PDFColorComponent PDFFloatBitmap::getPixelInkCoverage(size_t x, size_t y) const
+{
+    PDFConstColorBuffer buffer = getPixel(x, y);
+
+    const uint8_t colorChannelIndexStart = m_format.getColorChannelIndexStart();
+    const uint8_t colorChannelIndexEnd = m_format.getColorChannelIndexEnd();
+
+    PDFColorComponent inkCoverage = 0.0;
+    for (uint8_t i = colorChannelIndexStart; i < colorChannelIndexEnd; ++i)
+    {
+        inkCoverage += buffer[i];
+    }
+
+    return inkCoverage;
+}
+
 const PDFColorComponent* PDFFloatBitmap::begin() const
 {
     return m_data.data();
diff --git a/Pdf4QtLib/sources/pdftransparencyrenderer.h b/Pdf4QtLib/sources/pdftransparencyrenderer.h
index 856b01f..aa8d4e9 100644
--- a/Pdf4QtLib/sources/pdftransparencyrenderer.h
+++ b/Pdf4QtLib/sources/pdftransparencyrenderer.h
@@ -157,6 +157,9 @@ public:
     /// Returns buffer with all pixels
     PDFColorBuffer getPixels();
 
+    /// Returns ink coverage
+    PDFColorComponent getPixelInkCoverage(size_t x, size_t y) const;
+
     const PDFColorComponent* begin() const;
     const PDFColorComponent* end() const;
 
diff --git a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.cpp b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.cpp
index f7467af..a463915 100644
--- a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.cpp
+++ b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.cpp
@@ -69,11 +69,17 @@ OutputPreviewDialog::OutputPreviewDialog(const pdf::PDFDocument* document, pdf::
     connect(ui->displayVectorGraphicsCheckBox, &QCheckBox::clicked, this, &OutputPreviewDialog::updatePageImage);
     connect(ui->inksTreeWidget->model(), &QAbstractItemModel::dataChanged, this, &OutputPreviewDialog::onInksChanged);
     connect(ui->alarmColorButton, &QPushButton::clicked, this, &OutputPreviewDialog::onAlarmColorButtonClicked);
+    connect(ui->displayModeComboBox, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &OutputPreviewDialog::onDisplayModeChanged);
+    connect(ui->inkCoverageLimitEdit, QOverload<double>::of(&QDoubleSpinBox::valueChanged), this, &OutputPreviewDialog::onInkCoverageLimitChanged);
+    connect(ui->richBlackLimitEdit, QOverload<double>::of(&QDoubleSpinBox::valueChanged), this, &OutputPreviewDialog::onRichBlackLimtiChanged);
 
     updatePageImage();
     updateInks();
     updatePaperColorWidgets();
     updateAlarmColorButtonIcon();
+    onDisplayModeChanged();
+    onInkCoverageLimitChanged(ui->inkCoverageLimitEdit->value());
+    onRichBlackLimtiChanged(ui->richBlackLimitEdit->value());
 }
 
 OutputPreviewDialog::~OutputPreviewDialog()
@@ -220,6 +226,11 @@ void OutputPreviewDialog::onSimulatePaperColorChecked(bool checked)
     updatePageImage();
 }
 
+void OutputPreviewDialog::onDisplayModeChanged()
+{
+    ui->imageWidget->setDisplayMode(OutputPreviewWidget::DisplayMode(ui->displayModeComboBox->currentData().toInt()));
+}
+
 void OutputPreviewDialog::onInksChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight, const QVector<int>& roles)
 {
     Q_UNUSED(topLeft);
@@ -231,6 +242,16 @@ void OutputPreviewDialog::onInksChanged(const QModelIndex& topLeft, const QModel
     }
 }
 
+void OutputPreviewDialog::onInkCoverageLimitChanged(double value)
+{
+    ui->imageWidget->setInkCoverageLimit(value / 100.0);
+}
+
+void OutputPreviewDialog::onRichBlackLimtiChanged(double value)
+{
+    ui->imageWidget->setRichBlackLimit(value / 100.0);
+}
+
 void OutputPreviewDialog::updatePageImage()
 {
     if (!isRenderingDone())
diff --git a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.h b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.h
index 7110d8a..5e7ce55 100644
--- a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.h
+++ b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewdialog.h
@@ -59,7 +59,10 @@ private:
     void onAlarmColorButtonClicked();
     void onSimulateSeparationsChecked(bool checked);
     void onSimulatePaperColorChecked(bool checked);
+    void onDisplayModeChanged();
     void onInksChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight, const QVector<int>& roles);
+    void onInkCoverageLimitChanged(double value);
+    void onRichBlackLimtiChanged(double value);
 
     struct RenderedImage
     {
diff --git a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.cpp b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.cpp
index b87a72a..ca78590 100644
--- a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.cpp
+++ b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.cpp
@@ -30,7 +30,9 @@ OutputPreviewWidget::OutputPreviewWidget(QWidget* parent) :
     BaseClass(parent),
     m_inkMapper(nullptr),
     m_displayMode(Separations),
-    m_alarmColor(Qt::red)
+    m_alarmColor(Qt::red),
+    m_inkCoverageLimit(3.0),
+    m_richBlackLimit(1.0)
 {
     setMouseTracking(true);
 }
@@ -53,6 +55,8 @@ void OutputPreviewWidget::clear()
     m_infoBoxItems.clear();
     m_imagePointUnderCursor = std::nullopt;
     m_inkCoverageMM.dirty();
+    m_alarmCoverageImage.dirty();
+    m_alarmRichBlackImage.dirty();
     update();
 }
 
@@ -72,6 +76,8 @@ void OutputPreviewWidget::setPageImage(QImage image, pdf::PDFFloatBitmapWithColo
     }
 
     m_inkCoverageMM.dirty();
+    m_alarmCoverageImage.dirty();
+    m_alarmRichBlackImage.dirty();
 
     buildInfoBoxItems();
     update();
@@ -89,12 +95,52 @@ void OutputPreviewWidget::paintEvent(QPaintEvent* event)
     QRect contentRect = getContentRect();
     QRect pageImageRect = getPageImageRect(contentRect);
 
-    if (pageImageRect.isValid() && !m_pageImage.isNull())
+    if (pageImageRect.isValid())
     {
         painter.save();
         painter.setClipRect(pageImageRect, Qt::IntersectClip);
-        painter.translate(0, (pageImageRect.height() - m_pageImage.height()) / 2);
-        painter.drawImage(pageImageRect.topLeft(), m_pageImage);
+
+        switch (m_displayMode)
+        {
+            case Separations:
+            {
+                if (!m_pageImage.isNull())
+                {
+                    painter.translate(0, (pageImageRect.height() - m_pageImage.height()) / 2);
+                    painter.drawImage(pageImageRect.topLeft(), m_pageImage);
+                }
+                break;
+            }
+
+            case ColorWarningInkCoverage:
+            {
+                const QImage& image = getAlarmCoverageImage();
+                if (!image.isNull())
+                {
+                    painter.translate(0, (pageImageRect.height() - image.height()) / 2);
+                    painter.drawImage(pageImageRect.topLeft(), image);
+                }
+                break;
+            }
+
+            case ColorWarningRichBlack:
+            {
+                const QImage& image = getAlarmRichBlackImage();
+                if (!image.isNull())
+                {
+                    painter.translate(0, (pageImageRect.height() - image.height()) / 2);
+                    painter.drawImage(pageImageRect.topLeft(), image);
+                }
+                break;
+            }
+
+            case InkCoverage:
+                break;
+
+            default:
+                Q_ASSERT(false);
+        }
+
         painter.restore();
     }
 
@@ -411,6 +457,16 @@ const std::vector<pdf::PDFColorComponent>& OutputPreviewWidget::getInkCoverage()
     return m_inkCoverageMM.get(this, &OutputPreviewWidget::getInkCoverageImpl);
 }
 
+const QImage& OutputPreviewWidget::getAlarmCoverageImage() const
+{
+    return m_alarmCoverageImage.get(this, &OutputPreviewWidget::getAlarmCoverageImageImpl);
+}
+
+const QImage& OutputPreviewWidget::getAlarmRichBlackImage() const
+{
+    return m_alarmRichBlackImage.get(this, &OutputPreviewWidget::getAlarmRichBlackImageImpl);
+}
+
 std::vector<pdf::PDFColorComponent> OutputPreviewWidget::getInkCoverageImpl() const
 {
     std::vector<pdf::PDFColorComponent> result;
@@ -447,6 +503,111 @@ std::vector<pdf::PDFColorComponent> OutputPreviewWidget::getInkCoverageImpl() co
     return result;
 }
 
+QImage OutputPreviewWidget::getAlarmCoverageImageImpl() const
+{
+    QImage alarmImage = m_pageImage;
+
+    const int width = alarmImage.width();
+    const int height = alarmImage.height();
+
+    for (int y = 0; y < height; ++y)
+    {
+        for (int x = 0; x < width; ++x)
+        {
+            pdf::PDFColorComponent inkCoverage = m_originalProcessBitmap.getPixelInkCoverage(x, y);
+            if (inkCoverage > m_inkCoverageLimit)
+            {
+                alarmImage.setPixelColor(x, y, m_alarmColor);
+            }
+        }
+    }
+
+    return alarmImage;
+}
+
+QImage OutputPreviewWidget::getAlarmRichBlackImageImpl() const
+{
+    QImage alarmImage = m_pageImage;
+
+    const pdf::PDFPixelFormat pixelFormat = m_originalProcessBitmap.getPixelFormat();
+    if (pixelFormat.getProcessColorChannelCount() == 4)
+    {
+        const int width = alarmImage.width();
+        const int height = alarmImage.height();
+
+        const uint8_t blackChannelIndex = pixelFormat.getProcessColorChannelIndexStart() + 3;
+
+        for (int y = 0; y < height; ++y)
+        {
+            for (int x = 0; x < width; ++x)
+            {
+                pdf::PDFConstColorBuffer buffer = m_originalProcessBitmap.getPixel(x, y);
+                pdf::PDFColorComponent blackInk = buffer[blackChannelIndex];
+
+                if (blackInk > m_richBlackLimit)
+                {
+                    pdf::PDFColorComponent inkCoverage = m_originalProcessBitmap.getPixelInkCoverage(x, y);
+                    pdf::PDFColorComponent inkCoverageWithoutBlack = inkCoverage - blackInk;
+
+                    if (!qFuzzyIsNull(inkCoverageWithoutBlack))
+                    {
+                        alarmImage.setPixelColor(x, y, m_alarmColor);
+                    }
+                }
+            }
+        }
+    }
+
+    return alarmImage;
+}
+
+pdf::PDFColorComponent OutputPreviewWidget::getRichBlackLimit() const
+{
+    return m_richBlackLimit;
+}
+
+void OutputPreviewWidget::setRichBlackLimit(pdf::PDFColorComponent richBlackLimit)
+{
+    if (m_richBlackLimit != richBlackLimit)
+    {
+        m_richBlackLimit = richBlackLimit;
+        m_alarmRichBlackImage.dirty();
+        buildInfoBoxItems();
+        update();
+    }
+}
+
+pdf::PDFColorComponent OutputPreviewWidget::getInkCoverageLimit() const
+{
+    return m_inkCoverageLimit;
+}
+
+void OutputPreviewWidget::setInkCoverageLimit(pdf::PDFColorComponent inkCoverageLimit)
+{
+    if (m_inkCoverageLimit != inkCoverageLimit)
+    {
+        m_inkCoverageLimit = inkCoverageLimit;
+        m_alarmCoverageImage.dirty();
+        buildInfoBoxItems();
+        update();
+    }
+}
+
+OutputPreviewWidget::DisplayMode OutputPreviewWidget::getDisplayMode() const
+{
+    return m_displayMode;
+}
+
+void OutputPreviewWidget::setDisplayMode(const DisplayMode& displayMode)
+{
+    if (m_displayMode != displayMode)
+    {
+        m_displayMode = displayMode;
+        buildInfoBoxItems();
+        update();
+    }
+}
+
 QColor OutputPreviewWidget::getAlarmColor() const
 {
     return m_alarmColor;
@@ -454,7 +615,13 @@ QColor OutputPreviewWidget::getAlarmColor() const
 
 void OutputPreviewWidget::setAlarmColor(const QColor& alarmColor)
 {
-    m_alarmColor = alarmColor;
+    if (m_alarmColor != alarmColor)
+    {
+        m_alarmColor = alarmColor;
+        m_alarmCoverageImage.dirty();
+        m_alarmRichBlackImage.dirty();
+        update();
+    }
 }
 
 const pdf::PDFInkMapper* OutputPreviewWidget::getInkMapper() const
diff --git a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.h b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.h
index 90d2353..6edbba5 100644
--- a/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.h
+++ b/Pdf4QtViewerPlugins/OutputPreviewPlugin/outputpreviewwidget.h
@@ -61,6 +61,15 @@ public:
     QColor getAlarmColor() const;
     void setAlarmColor(const QColor& alarmColor);
 
+    DisplayMode getDisplayMode() const;
+    void setDisplayMode(const DisplayMode& displayMode);
+
+    pdf::PDFColorComponent getInkCoverageLimit() const;
+    void setInkCoverageLimit(pdf::PDFColorComponent inkCoverageLimit);
+
+    pdf::PDFColorComponent getRichBlackLimit() const;
+    void setRichBlackLimit(pdf::PDFColorComponent richBlackLimit);
+
 protected:
     virtual void paintEvent(QPaintEvent* event) override;
     virtual void mouseMoveEvent(QMouseEvent* event) override;
@@ -80,8 +89,12 @@ private:
     void addInfoBoxColoredRect(QColor color);
 
     const std::vector<pdf::PDFColorComponent>& getInkCoverage() const;
+    const QImage& getAlarmCoverageImage() const;
+    const QImage& getAlarmRichBlackImage() const;
 
     std::vector<pdf::PDFColorComponent> getInkCoverageImpl() const;
+    QImage getAlarmCoverageImageImpl() const;
+    QImage getAlarmRichBlackImageImpl() const;
 
     enum InfoBoxStyle
     {
@@ -113,8 +126,12 @@ private:
     std::vector<InfoBoxItem> m_infoBoxItems;
     QColor m_alarmColor;
     std::optional<QPoint> m_imagePointUnderCursor;
+    pdf::PDFColorComponent m_inkCoverageLimit;
+    pdf::PDFColorComponent m_richBlackLimit;
 
     mutable pdf::PDFCachedItem<std::vector<pdf::PDFColorComponent>> m_inkCoverageMM;
+    mutable pdf::PDFCachedItem<QImage> m_alarmCoverageImage;
+    mutable pdf::PDFCachedItem<QImage> m_alarmRichBlackImage;
 
     QImage m_pageImage;
     pdf::PDFFloatBitmapWithColorSpace m_originalProcessBitmap;