diff --git a/src/AppFrame.cpp b/src/AppFrame.cpp
index 93869c0..7030e00 100644
--- a/src/AppFrame.cpp
+++ b/src/AppFrame.cpp
@@ -158,6 +158,20 @@ AppFrame::AppFrame() :
 
     menuBar->Append(menu, wxT("Active Demodulator &Output"));
 
+
+    menu = new wxMenu;
+
+    menu->Append(wxID_THEME_DEFAULT, "Default");
+    menu->Append(wxID_THEME_RADAR, "RADAR");
+    menu->Append(wxID_THEME_BW, "Black & White");
+    menu->Append(wxID_THEME_SHARP, "Sharp");
+    menu->Append(wxID_THEME_RAD, "Rad");
+    menu->Append(wxID_THEME_TOUCH, "Touch");
+    menu->Append(wxID_THEME_HD, "HD");
+
+    menuBar->Append(menu, wxT("&Color Scheme"));
+
+
     SetMenuBar(menuBar);
 
     CreateStatusBar();
@@ -226,6 +240,27 @@ void AppFrame::OnMenu(wxCommandEvent& event) {
         currentSessionFile = "";
     } else if (event.GetId() == wxID_EXIT) {
         Close(false);
+    } else if (event.GetId() == wxID_THEME_DEFAULT) {
+        waterfallCanvas->setTheme(COLOR_THEME_DEFAULT);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_DEFAULT);
+    } else if (event.GetId() == wxID_THEME_SHARP) {
+        waterfallCanvas->setTheme(COLOR_THEME_SHARP);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_SHARP);
+    } else if (event.GetId() == wxID_THEME_BW) {
+        waterfallCanvas->setTheme(COLOR_THEME_BW);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_BW);
+    } else if (event.GetId() == wxID_THEME_RAD) {
+        waterfallCanvas->setTheme(COLOR_THEME_RAD);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_RAD);
+    } else if (event.GetId() == wxID_THEME_TOUCH) {
+        waterfallCanvas->setTheme(COLOR_THEME_TOUCH);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_TOUCH);
+    } else if (event.GetId() == wxID_THEME_HD) {
+        waterfallCanvas->setTheme(COLOR_THEME_HD);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_HD);
+    } else if (event.GetId() == wxID_THEME_RADAR) {
+        waterfallCanvas->setTheme(COLOR_THEME_RADAR);
+        demodWaterfallCanvas->setTheme(COLOR_THEME_RADAR);
     }
 }
 
diff --git a/src/AppFrame.h b/src/AppFrame.h
index d773b94..893cb31 100644
--- a/src/AppFrame.h
+++ b/src/AppFrame.h
@@ -16,6 +16,14 @@
 #define wxID_SET_FREQ_OFFSET 2001
 #define wxID_RESET 2002
 
+#define wxID_THEME_DEFAULT 2100
+#define wxID_THEME_SHARP 2101
+#define wxID_THEME_BW 2102
+#define wxID_THEME_RAD 2103
+#define wxID_THEME_TOUCH 2104
+#define wxID_THEME_HD 2105
+#define wxID_THEME_RADAR 2106
+
 // Define a new frame type
 class AppFrame: public wxFrame {
 public:
diff --git a/src/demod/DemodulatorInstance.cpp b/src/demod/DemodulatorInstance.cpp
index 5645948..3981658 100644
--- a/src/demod/DemodulatorInstance.cpp
+++ b/src/demod/DemodulatorInstance.cpp
@@ -183,7 +183,7 @@ void DemodulatorInstance::squelchAuto() {
 }
 
 bool DemodulatorInstance::isSquelchEnabled() {
-    return squelch;
+    return (demodulatorThread->getSquelchLevel() != 0.0);
 }
 
 void DemodulatorInstance::setSquelchEnabled(bool state) {
diff --git a/src/util/Gradient.cpp b/src/util/Gradient.cpp
index 0dba7ca..fed05ac 100644
--- a/src/util/Gradient.cpp
+++ b/src/util/Gradient.cpp
@@ -29,8 +29,8 @@ void Gradient::generate(unsigned int len) {
     b_val.resize(len);
 
     for (unsigned int j = 0, jMax = colors.size() - 1; j < jMax; j++) {
-        if (chunk_size * (jMax + 1) < len && j == jMax - 1) {
-            chunk_size += len - chunk_size * (jMax + 1);
+        if ((chunk_size * (jMax)) < len && (j == jMax - 1)) {
+            chunk_size += len - chunk_size * (jMax);
         }
 
         for (unsigned int i = 0; i < chunk_size; i++) {
diff --git a/src/visual/WaterfallCanvas.cpp b/src/visual/WaterfallCanvas.cpp
index 50238f3..f2540cd 100644
--- a/src/visual/WaterfallCanvas.cpp
+++ b/src/visual/WaterfallCanvas.cpp
@@ -36,7 +36,7 @@ wxEND_EVENT_TABLE()
 WaterfallCanvas::WaterfallCanvas(wxWindow *parent, int *attribList) :
         InteractiveCanvas(parent, attribList), spectrumCanvas(NULL), dragState(WF_DRAG_NONE), nextDragState(WF_DRAG_NONE), fft_size(0), waterfall_lines(
                 0), plan(
-        NULL), in(NULL), out(NULL), resampler(NULL), resamplerRatio(0), lastInputBandwidth(0), zoom(1), mouseZoom(1) {
+        NULL), in(NULL), out(NULL), resampler(NULL), resamplerRatio(0), lastInputBandwidth(0), zoom(1), mouseZoom(1), theme(0) {
 
     glContext = new WaterfallContext(this, &wxGetApp().GetContext(this));
 
@@ -95,6 +95,11 @@ void WaterfallCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) {
     glContext->SetCurrent(*this);
     glViewport(0, 0, ClientSize.x, ClientSize.y);
 
+    if (theme != glContext->getTheme()) {
+        glContext->setTheme(theme);
+        theme = glContext->getTheme();
+    }
+
     glContext->BeginDraw();
     glContext->Draw(spectrum_points);
 
@@ -824,3 +829,11 @@ void WaterfallCanvas::OnMouseRightReleased(wxMouseEvent& event) {
     mouseTracker.setHorizDragLock(false);
     mouseZoom = 1.0;
 }
+
+void WaterfallCanvas::setTheme(int theme_id) {
+    theme = theme_id;
+}
+
+int WaterfallCanvas::getTheme() {
+    return glContext->getTheme();
+}
diff --git a/src/visual/WaterfallCanvas.h b/src/visual/WaterfallCanvas.h
index 7ab97e9..c8c8933 100644
--- a/src/visual/WaterfallCanvas.h
+++ b/src/visual/WaterfallCanvas.h
@@ -29,6 +29,8 @@ public:
     DragState getNextDragState();
 
     void attachSpectrumCanvas(SpectrumCanvas *canvas_in);
+    void setTheme(int theme_id);
+    int getTheme();
 
 private:
     void OnPaint(wxPaintEvent& event);
@@ -75,6 +77,8 @@ private:
     int lastInputBandwidth;
     float mouseZoom, zoom;
 
+    int theme;
+
     std::vector<liquid_float_complex> shiftBuffer;
     std::vector<liquid_float_complex> resampleBuffer;
     // event table
diff --git a/src/visual/WaterfallContext.cpp b/src/visual/WaterfallContext.cpp
index c8a732c..4284d69 100644
--- a/src/visual/WaterfallContext.cpp
+++ b/src/visual/WaterfallContext.cpp
@@ -3,14 +3,83 @@
 #include "CubicSDR.h"
 
 WaterfallContext::WaterfallContext(WaterfallCanvas *canvas, wxGLContext *sharedContext) :
-        PrimaryGLContext(canvas, sharedContext), waterfall(0), waterfall_tex(NULL) {
-    grad.addColor(GradientColor(0, 0, 0));
-    grad.addColor(GradientColor(0, 0, 1.0));
-    grad.addColor(GradientColor(0, 1.0, 0));
-    grad.addColor(GradientColor(1.0, 1.0, 0));
-    grad.addColor(GradientColor(1.0, 0.2, 0.0));
+        PrimaryGLContext(canvas, sharedContext), waterfall(0), waterfall_tex(NULL), waterfall_lines(0), fft_size(0), theme(COLOR_THEME_DEFAULT) {
+    Gradient *grad = new Gradient();
+    grad->addColor(GradientColor(0, 0, 0));
+    grad->addColor(GradientColor(0, 0, 1.0));
+    grad->addColor(GradientColor(0, 1.0, 0));
+    grad->addColor(GradientColor(1.0, 1.0, 0));
+    grad->addColor(GradientColor(1.0, 0.2, 0.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_DEFAULT] = grad;
 
-    grad.generate(256);
+    grad = new Gradient();
+    grad->addColor(GradientColor(0, 0, 0));
+    grad->addColor(GradientColor(0.0, 0, 0.5));
+    grad->addColor(GradientColor(0.0, 0.0, 1.0));
+    grad->addColor(GradientColor(65.0 / 255.0, 161.0 / 255.0, 1.0));
+    grad->addColor(GradientColor(1.0, 1.0, 1.0));
+    grad->addColor(GradientColor(1.0, 1.0, 1.0));
+    grad->addColor(GradientColor(1.0, 1.0, 0.5));
+    grad->addColor(GradientColor(1.0, 1.0, 0.0));
+    grad->addColor(GradientColor(1.0, 0.5, 0.0));
+    grad->addColor(GradientColor(1.0, 0.25, 0.0));
+    grad->addColor(GradientColor(0.5, 0.1, 0.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_SHARP] = grad;
+
+    grad = new Gradient();
+    grad->addColor(GradientColor(0, 0, 0));
+    grad->addColor(GradientColor(0.75, 0.75, 0.75));
+    grad->addColor(GradientColor(1.0, 1.0, 1.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_BW] = grad;
+
+    grad = new Gradient();
+    grad->addColor(GradientColor(0, 0, 0.5));
+    grad->addColor(GradientColor(25.0/255.0, 154.0/255.0, 0.0));
+    grad->addColor(GradientColor(201.0/255.0, 115.0/255.0, 0.0));
+    grad->addColor(GradientColor(1.0, 40.0/255.0, 40.0/255.0));
+    grad->addColor(GradientColor(1.0, 1.0, 1.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_RAD] = grad;
+
+
+    grad = new Gradient();
+    grad->addColor(GradientColor(0, 0, 0));
+    grad->addColor(GradientColor(55.0/255.0, 40.0/255.0, 55.0/255.0));
+    grad->addColor(GradientColor(60.0/255.0, 60.0/255.0, 90.0/255.0));
+    grad->addColor(GradientColor(0.0/255.0, 255.0/255.0, 255.0/255.0));
+    grad->addColor(GradientColor(10.0/255.0, 255.0/255.0, 85.0/255.0));
+    grad->addColor(GradientColor(255.0/255.0, 255.0/255.0, 75.0/255.0));
+    grad->addColor(GradientColor(255.0/255.0, 0.0/255.0, 0.0/255.0));
+    grad->addColor(GradientColor(255.0/255.0, 255.0/255.0, 255.0/255.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_TOUCH] = grad;
+
+
+    grad = new Gradient();
+    grad->addColor(GradientColor(5.0/255.0, 5.0/255.0, 60.0/255.0));
+    grad->addColor(GradientColor(5.0/255.0, 20.0/255.0, 120.0/255.0));
+    grad->addColor(GradientColor(50.0/255.0, 100.0/255.0, 200.0/255.0));
+    grad->addColor(GradientColor(75.0/255.0, 190.0/255.0, 100.0/255.0));
+    grad->addColor(GradientColor(240.0/255.0, 55.0/255.0, 5.0/255.0));
+    grad->addColor(GradientColor(255.0/255.0, 55.0/255.0, 100.0/255.0));
+    grad->addColor(GradientColor(255.0/255.0, 235.0/255.0, 100.0/255.0));
+    grad->addColor(GradientColor(250.0/255.0, 250.0/255.0, 250.0/255.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_HD] = grad;
+
+
+
+
+    grad = new Gradient();
+    grad->addColor(GradientColor(5.0/255.0, 45.0/255.0, 10.0/255.0));
+    grad->addColor(GradientColor(30.0/255.0, 150.0/255.0, 40.0/255.0));
+    grad->addColor(GradientColor(40.0/255.0, 240.0/255.0, 60.0/255.0));
+    grad->addColor(GradientColor(250.0/255.0, 250.0/255.0, 250.0/255.0));
+    grad->generate(256);
+    gradients[COLOR_THEME_RADAR] = grad;
 }
 
 void WaterfallContext::Setup(int fft_size_in, int num_waterfall_lines_in) {
@@ -26,7 +95,7 @@ void WaterfallContext::Setup(int fft_size_in, int num_waterfall_lines_in) {
     fft_size = fft_size_in;
 
     waterfall_tex = new unsigned char[fft_size * waterfall_lines];
-    memset(waterfall_tex,0,fft_size * waterfall_lines);
+    memset(waterfall_tex, 0, fft_size * waterfall_lines);
 
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
@@ -46,12 +115,30 @@ void WaterfallContext::Setup(int fft_size_in, int num_waterfall_lines_in) {
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 
     glPixelTransferi(GL_MAP_COLOR, GL_TRUE);
-    glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 256, &(grad.getRed())[0]);
-    glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 256, &(grad.getGreen())[0]);
-    glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 256, &(grad.getBlue())[0]);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 256, &(gradients[theme]->getRed())[0]);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 256, &(gradients[theme]->getGreen())[0]);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 256, &(gradients[theme]->getBlue())[0]);
 
 }
 
+void WaterfallContext::setTheme(int theme_id) {
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, waterfall);
+
+    if (theme >= COLOR_THEME_MAX) {
+        theme = COLOR_THEME_MAX - 1;
+    }
+    if (theme < 0) {
+        theme = 0;
+    }
+    theme = theme_id;
+
+    glPixelTransferi(GL_MAP_COLOR, GL_TRUE);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_R, 256, &(gradients[theme]->getRed())[0]);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_G, 256, &(gradients[theme]->getGreen())[0]);
+    glPixelMapfv(GL_PIXEL_MAP_I_TO_B, 256, &(gradients[theme]->getBlue())[0]);
+}
+
 void WaterfallContext::Draw(std::vector<float> &points) {
 
     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
@@ -65,8 +152,8 @@ void WaterfallContext::Draw(std::vector<float> &points) {
             float wv = v;
             if (wv < 0.0)
                 wv = 0.0;
-            if (wv > 1.0)
-                wv = 1.0;
+            if (wv > 0.99)
+                wv = 0.99;
             waterfall_tex[i] = (unsigned char) floor(wv * 255.0);
         }
     }
@@ -94,3 +181,6 @@ void WaterfallContext::Draw(std::vector<float> &points) {
 
 }
 
+int WaterfallContext::getTheme() {
+    return theme;
+}
diff --git a/src/visual/WaterfallContext.h b/src/visual/WaterfallContext.h
index 535b254..5677b93 100644
--- a/src/visual/WaterfallContext.h
+++ b/src/visual/WaterfallContext.h
@@ -3,6 +3,16 @@
 #include "PrimaryGLContext.h"
 #include "Gradient.h"
 
+
+#define COLOR_THEME_DEFAULT 0
+#define COLOR_THEME_BW 1
+#define COLOR_THEME_SHARP 2
+#define COLOR_THEME_RAD 3
+#define COLOR_THEME_TOUCH 4
+#define COLOR_THEME_HD 5
+#define COLOR_THEME_RADAR 6
+#define COLOR_THEME_MAX 7
+
 class WaterfallCanvas;
 
 class WaterfallContext: public PrimaryGLContext {
@@ -11,10 +21,13 @@ public:
 
     void Draw(std::vector<float> &points);
     void Setup(int fft_size_in, int num_waterfall_lines_in);
+    void setTheme(int theme_id);
+    int getTheme();
 
 private:
-    Gradient grad;
+    Gradient *gradients[COLOR_THEME_MAX];
     GLuint waterfall;
+    int theme;
     unsigned char *waterfall_tex;
     int fft_size;
     int waterfall_lines;