diff --git a/sdrgui/gui/glspectrum.cpp b/sdrgui/gui/glspectrum.cpp
index 7b284bcd5..553481529 100644
--- a/sdrgui/gui/glspectrum.cpp
+++ b/sdrgui/gui/glspectrum.cpp
@@ -1163,8 +1163,7 @@ void GLSpectrum::paintGL()
 
 void GLSpectrum::drawMarkers()
 {
-    QVector4D markerColor(1.0f, 1.0f, 1.0f, 0.3f);
-    QVector4D markerTextColor(1.0f, 1.0f, 1.0f, 0.8f);
+	QVector4D lineColor(1.0f, 1.0f, 1.0f, 0.3f);
 
     // paint histogram markers
     if (m_histogramMarkers.size() > 0)
@@ -1178,7 +1177,9 @@ void GLSpectrum::drawMarkers()
 			{
 				ypoint.ry() =
 					(m_powerScale.getRangeMax() - m_currentSpectrum[m_histogramMarkers.at(i).m_fftBin]) / m_powerScale.getRange();
-				ypoint.ry() = ypoint.ry() > 1 ? 1 : ypoint.ry();
+				ypoint.ry() = ypoint.ry() < 0 ?
+					0 : ypoint.ry() > 1 ?
+						1 : ypoint.ry();
 				powerStr = displayScaledF(
 					m_currentSpectrum[m_histogramMarkers.at(i).m_fftBin],
 					m_linear ? 'e' : 'f',
@@ -1192,18 +1193,19 @@ void GLSpectrum::drawMarkers()
                 (float) m_histogramMarkers.at(i).m_point.x(), 0,
                 (float) m_histogramMarkers.at(i).m_point.x(), 1
             };
-            m_glShaderSimple.drawSegments(m_glHistogramBoxMatrix, markerColor, h, 2);
+            m_glShaderSimple.drawSegments(m_glHistogramBoxMatrix, lineColor, h, 2);
             GLfloat v[] {
                 0, (float) ypoint.y(),
                 1, (float) ypoint.y()
             };
-            m_glShaderSimple.drawSegments(m_glHistogramBoxMatrix, markerColor, v, 2);
+            m_glShaderSimple.drawSegments(m_glHistogramBoxMatrix, lineColor, v, 2);
+			QColor textColor = m_histogramMarkers.at(i).m_markerColor;
 			// text
             if (i == 0)
             {
                 drawTextOverlay(
                     m_histogramMarkers.at(i).m_frequencyStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_histogramMarkers.at(i).m_point.x() * m_histogramRect.width(),
                     (m_invertedWaterfall || (m_waterfallHeight == 0)) ? m_histogramRect.height() : 0,
@@ -1212,7 +1214,7 @@ void GLSpectrum::drawMarkers()
                     m_histogramRect);
                 drawTextOverlay(
                     powerStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     0,
                     ypoint.y() * m_histogramRect.height(),
@@ -1222,6 +1224,7 @@ void GLSpectrum::drawMarkers()
             }
             else
             {
+				textColor.setAlpha(192);
 				float power0 = m_histogramMarkers.at(0).m_markerType == SpectrumHistogramMarkerTypePower ?
 					m_currentSpectrum[m_histogramMarkers.at(0).m_fftBin] :
 					m_linear ? m_histogramMarkers.at(0).m_power : CalcDb::dbPower(m_histogramMarkers.at(0).m_power);
@@ -1238,7 +1241,7 @@ void GLSpectrum::drawMarkers()
 
                 drawTextOverlay(
                     m_histogramMarkers.at(i).m_deltaFrequencyStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_histogramMarkers.at(i).m_point.x() * m_histogramRect.width(),
                     (m_invertedWaterfall || (m_waterfallHeight == 0)) ? 0 : m_histogramRect.height(),
@@ -1247,7 +1250,7 @@ void GLSpectrum::drawMarkers()
                     m_histogramRect);
                 drawTextOverlay(
                     deltaPowerStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_histogramRect.width(),
                     ypoint.y() * m_histogramRect.height(),
@@ -1268,21 +1271,24 @@ void GLSpectrum::drawMarkers()
                 (float) m_waterfallMarkers.at(i).m_point.x(), 0,
                 (float) m_waterfallMarkers.at(i).m_point.x(), 1
             };
-            m_glShaderSimple.drawSegments(m_glWaterfallBoxMatrix, markerColor, h, 2);
+            m_glShaderSimple.drawSegments(m_glWaterfallBoxMatrix, lineColor, h, 2);
             GLfloat v[] {
                 0, (float) m_waterfallMarkers.at(i).m_point.y(),
                 1, (float) m_waterfallMarkers.at(i).m_point.y()
             };
-            m_glShaderSimple.drawSegments(m_glWaterfallBoxMatrix, markerColor, v, 2);
+            m_glShaderSimple.drawSegments(m_glWaterfallBoxMatrix, lineColor, v, 2);
         }
         // text
         for (int i = 0; i < m_waterfallMarkers.size(); i++)
         {
+			QColor textColor = m_waterfallMarkers.at(i).m_markerColor;
+			textColor.setAlpha(192);
+
             if (i == 0)
             {
                 drawTextOverlay(
                     m_waterfallMarkers.at(i).m_frequencyStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_waterfallMarkers.at(i).m_point.x() * m_waterfallRect.width(),
                     (!m_invertedWaterfall || (m_histogramHeight == 0)) ? m_waterfallRect.height() : 0,
@@ -1291,7 +1297,7 @@ void GLSpectrum::drawMarkers()
                     m_waterfallRect);
                 drawTextOverlay(
                     m_waterfallMarkers.at(i).m_timeStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     0,
                     m_waterfallMarkers.at(i).m_point.y() * m_waterfallRect.height(),
@@ -1303,7 +1309,7 @@ void GLSpectrum::drawMarkers()
             {
                 drawTextOverlay(
                     m_waterfallMarkers.at(i).m_deltaFrequencyStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_waterfallMarkers.at(i).m_point.x() * m_waterfallRect.width(),
                     (!m_invertedWaterfall || (m_histogramHeight == 0)) ? 0 : m_waterfallRect.height(),
@@ -1312,7 +1318,7 @@ void GLSpectrum::drawMarkers()
                     m_waterfallRect);
                 drawTextOverlay(
                     m_waterfallMarkers.at(i).m_deltaTimeStr,
-                    QColor(255, 255, 255, 192),
+                    textColor,
                     m_textOverlayFont,
                     m_waterfallRect.width(),
                     m_waterfallMarkers.at(i).m_point.y() * m_waterfallRect.height(),
diff --git a/sdrgui/gui/spectrummarkers.h b/sdrgui/gui/spectrummarkers.h
index a7f5118b1..e3f08f3aa 100644
--- a/sdrgui/gui/spectrummarkers.h
+++ b/sdrgui/gui/spectrummarkers.h
@@ -23,6 +23,7 @@
 
 #include <QString>
 #include <QPointF>
+#include <QColor>
 
 enum SpectrumHistogramMarkerType {
     SpectrumHistogramMarkerTypeManual,
@@ -36,6 +37,7 @@ struct SpectrumHistogramMarker
     int m_fftBin;
     float m_power;
     SpectrumHistogramMarkerType m_markerType;
+    QColor m_markerColor;
     QString m_frequencyStr;
     QString m_powerStr;
     QString m_deltaFrequencyStr;
@@ -48,6 +50,7 @@ struct SpectrumHistogramMarker
         m_fftBin(0),
         m_power(0),
         m_markerType(SpectrumHistogramMarkerTypeManual),
+        m_markerColor(QColorConstants::White),
         m_frequencyStr(),
         m_powerStr(),
         m_deltaFrequencyStr(),
@@ -60,6 +63,7 @@ struct SpectrumHistogramMarker
         int   fftBin,
         float power,
         SpectrumHistogramMarkerType markerType,
+        QColor markerColor,
         const QString& frequencyStr,
         const QString& powerStr,
         const QString& deltaFrequencyStr,
@@ -70,6 +74,7 @@ struct SpectrumHistogramMarker
         m_fftBin(fftBin),
         m_power(power),
         m_markerType(markerType),
+        m_markerColor(markerColor),
         m_frequencyStr(frequencyStr),
         m_powerStr(powerStr),
         m_deltaFrequencyStr(deltaFrequencyStr),
@@ -85,6 +90,7 @@ struct SpectrumWaterfallMarker
     QPointF m_point;
     float m_frequency;
     float m_time;
+    QColor m_markerColor;
     QString m_frequencyStr;
     QString m_timeStr;
     QString m_deltaFrequencyStr;
@@ -95,6 +101,7 @@ struct SpectrumWaterfallMarker
         m_point(0, 0),
         m_frequency(0),
         m_time(0),
+        m_markerColor(QColorConstants::White),
         m_frequencyStr(),
         m_timeStr(),
         m_deltaFrequencyStr(),
@@ -105,6 +112,7 @@ struct SpectrumWaterfallMarker
         const QPointF& point,
         float frequency,
         float time,
+        QColor markerColor,
         const QString& frequencyStr,
         const QString& timeStr,
         const QString& deltaFrequencyStr,
@@ -113,6 +121,7 @@ struct SpectrumWaterfallMarker
         m_point(point),
         m_frequency(frequency),
         m_time(time),
+        m_markerColor(markerColor),
         m_frequencyStr(frequencyStr),
         m_timeStr(timeStr),
         m_deltaFrequencyStr(deltaFrequencyStr),
diff --git a/sdrgui/gui/spectrummarkersdialog.cpp b/sdrgui/gui/spectrummarkersdialog.cpp
index eda9ee68d..a20d483bf 100644
--- a/sdrgui/gui/spectrummarkersdialog.cpp
+++ b/sdrgui/gui/spectrummarkersdialog.cpp
@@ -16,6 +16,8 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.          //
 ///////////////////////////////////////////////////////////////////////////////////
 
+#include <QColorDialog>
+
 #include "util/db.h"
 #include "spectrummarkersdialog.h"
 
@@ -68,6 +70,9 @@ void SpectrumMarkersDialog::displayHistogramMarker()
         float powerDB = CalcDb::dbPower(m_histogramMarkers[m_histogramMarkerIndex].m_power);
         ui->fixedPower->setValue(powerDB*10);
         ui->fixedPowerText->setText(QString::number(powerDB, 'f', 1));
+        int r,g,b,a;
+        m_histogramMarkers[m_histogramMarkerIndex].m_markerColor.getRgb(&r, &g, &b, &a);
+        ui->markerColor->setStyleSheet(tr("QLabel { background-color : rgb(%1,%2,%3); }").arg(r).arg(g).arg(b));
     }
 }
 
@@ -81,6 +86,37 @@ void SpectrumMarkersDialog::on_markerFrequency_changed(qint64 value)
     emit updateHistogram();
 }
 
+void SpectrumMarkersDialog::on_centerFrequency_clicked()
+{
+    if (m_histogramMarkers.size() == 0) {
+        return;
+    }
+
+    m_histogramMarkers[m_histogramMarkerIndex].m_frequency = m_centerFrequency;
+    displayHistogramMarker();
+    emit updateHistogram();
+}
+
+void SpectrumMarkersDialog::on_markerColor_clicked()
+{
+    if (m_histogramMarkers.size() == 0) {
+        return;
+    }
+
+    QColor newColor = QColorDialog::getColor(
+        m_histogramMarkers[m_histogramMarkerIndex].m_markerColor,
+        this,
+        tr("Select Color for marker"),
+        QColorDialog::DontUseNativeDialog
+    );
+
+    if (newColor.isValid()) // user clicked OK and selected a color
+    {
+        m_histogramMarkers[m_histogramMarkerIndex].m_markerColor = newColor;
+        displayHistogramMarker();
+    }
+}
+
 void SpectrumMarkersDialog::on_fixedPower_valueChanged(int value)
 {
     if (m_histogramMarkers.size() == 0) {
@@ -103,25 +139,25 @@ void SpectrumMarkersDialog::on_marker_valueChanged(int value)
     displayHistogramMarker();
 }
 
-void SpectrumMarkersDialog::on_setReference_clicked(bool checked)
+void SpectrumMarkersDialog::on_setReference_clicked()
 {
-    (void) checked;
-
     if ((m_histogramMarkerIndex == 0) || (m_histogramMarkers.size() < 2)) {
         return;
     }
 
     SpectrumHistogramMarker marker0 = m_histogramMarkers.at(0);
+    QColor color0 = marker0.m_markerColor; // do not exchange colors
+    QColor colorI = m_histogramMarkers[m_histogramMarkerIndex].m_markerColor;
     m_histogramMarkers[0] = m_histogramMarkers[m_histogramMarkerIndex];
+    m_histogramMarkers[0].m_markerColor = color0;
     m_histogramMarkers[m_histogramMarkerIndex] = marker0;
+    m_histogramMarkers[m_histogramMarkerIndex].m_markerColor = colorI;
     displayHistogramMarker();
     emit updateHistogram();
 }
 
-void SpectrumMarkersDialog::on_markerAdd_clicked(bool checked)
+void SpectrumMarkersDialog::on_markerAdd_clicked()
 {
-    (void) checked;
-
     if (m_histogramMarkers.size() == SpectrumHistogramMarker::m_maxNbOfMarkers) {
         return;
     }
@@ -134,10 +170,8 @@ void SpectrumMarkersDialog::on_markerAdd_clicked(bool checked)
     displayHistogramMarker();
 }
 
-void SpectrumMarkersDialog::on_markerDel_clicked(bool checked)
+void SpectrumMarkersDialog::on_markerDel_clicked()
 {
-    (void) checked;
-
     if (m_histogramMarkers.size() == 0) {
         return;
     }
diff --git a/sdrgui/gui/spectrummarkersdialog.h b/sdrgui/gui/spectrummarkersdialog.h
index 446f12259..1ab6150aa 100644
--- a/sdrgui/gui/spectrummarkersdialog.h
+++ b/sdrgui/gui/spectrummarkersdialog.h
@@ -54,11 +54,13 @@ private:
 
 private slots:
     void on_markerFrequency_changed(qint64 value);
+    void on_centerFrequency_clicked();
+    void on_markerColor_clicked();
     void on_fixedPower_valueChanged(int value);
     void on_marker_valueChanged(int value);
-    void on_setReference_clicked(bool checked);
-    void on_markerAdd_clicked(bool checked);
-    void on_markerDel_clicked(bool checked);
+    void on_setReference_clicked();
+    void on_markerAdd_clicked();
+    void on_markerDel_clicked();
     void on_powerMode_currentIndexChanged(int index);
 
 signals:
diff --git a/sdrgui/gui/spectrummarkersdialog.ui b/sdrgui/gui/spectrummarkersdialog.ui
index 529cf2e0f..2b1a4995e 100644
--- a/sdrgui/gui/spectrummarkersdialog.ui
+++ b/sdrgui/gui/spectrummarkersdialog.ui
@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>324</width>
+    <width>364</width>
     <height>125</height>
    </rect>
   </property>
@@ -23,7 +23,7 @@
    <item>
     <layout class="QVBoxLayout" name="MarkerLayout">
      <item>
-      <layout class="QHBoxLayout" name="MarkerPosLayout">
+      <layout class="QHBoxLayout" name="HMarkerPosLayout">
        <item>
         <widget class="QLabel" name="markerFrequencyLabel">
          <property name="text">
@@ -103,10 +103,48 @@
          </property>
         </spacer>
        </item>
+       <item>
+        <widget class="QPushButton" name="centerFrequency">
+         <property name="maximumSize">
+          <size>
+           <width>24</width>
+           <height>24</height>
+          </size>
+         </property>
+         <property name="toolTip">
+          <string>Set marker as reference (index 0)</string>
+         </property>
+         <property name="text">
+          <string>C</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="ClickableLabel" name="markerColor">
+         <property name="minimumSize">
+          <size>
+           <width>16</width>
+           <height>16</height>
+          </size>
+         </property>
+         <property name="maximumSize">
+          <size>
+           <width>16</width>
+           <height>16</height>
+          </size>
+         </property>
+         <property name="toolTip">
+          <string>Current marker color (click to change)</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+        </widget>
+       </item>
       </layout>
      </item>
      <item>
-      <layout class="QHBoxLayout" name="OptionsLayout">
+      <layout class="QHBoxLayout" name="HMarkerOptionsLayout">
        <item>
         <widget class="QLabel" name="markerLabel">
          <property name="minimumSize">
@@ -167,7 +205,7 @@
           <string>Set marker as reference (index 0)</string>
          </property>
          <property name="text">
-          <string>R</string>
+          <string>0</string>
          </property>
         </widget>
        </item>
@@ -406,6 +444,11 @@
    <header>gui/valuedialz.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>ClickableLabel</class>
+   <extends>QLabel</extends>
+   <header>gui/clickablelabel.h</header>
+  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>buttonBox</tabstop>