diff --git a/src/gui/waterfallview.cc b/src/gui/waterfallview.cc
index e36b62b..afcfe6b 100644
--- a/src/gui/waterfallview.cc
+++ b/src/gui/waterfallview.cc
@@ -41,7 +41,37 @@ GrayScaleColorMap::map(const double &value) {
 
 
 /* ****************************************************************************************** *
- *  Implementation of GrayScaleColorMap
+ *  Implementation of LinearColorMap
+ * ****************************************************************************************** */
+LinearColorMap::LinearColorMap(const QVector<QColor> &colors, double min, double max)
+  : ColorMap(min, max), _colors(colors)
+{
+  // pass...
+}
+
+LinearColorMap::~LinearColorMap() {
+  // pass...
+}
+
+QColor
+LinearColorMap::map(const double &value) {
+  // Calc indices
+  double upper = ceil(value*(_colors.size()-1));
+  double lower = floor(value*(_colors.size()-1));
+  int idx = int(lower);
+  if (lower == upper) { return _colors[idx]; }
+  double dv = upper-(value*(_colors.size()-1));
+  double dr = dv * (_colors[idx].red()   - _colors[idx+1].red());
+  double dg = dv * (_colors[idx].green() - _colors[idx+1].green());
+  double db = dv * (_colors[idx].blue()  - _colors[idx+1].blue());
+  return QColor(int(_colors[idx+1].red()+dr),
+                int(_colors[idx+1].green()+dg),
+                int(_colors[idx+1].blue()+db));
+}
+
+
+/* ****************************************************************************************** *
+ *  Implementation of WaterFallView
  * ****************************************************************************************** */
 WaterFallView::WaterFallView(Spectrum *spectrum, size_t height, QWidget *parent)
   : QWidget(parent), _spectrum(spectrum), _N(_spectrum->fftSize()), _M(height), _waterfall(_N,_M)
@@ -49,7 +79,10 @@ WaterFallView::WaterFallView(Spectrum *spectrum, size_t height, QWidget *parent)
   // Fill waterfall pixmap
   _waterfall.fill(Qt::black);
   // Create color map
-  _colorMap = new GrayScaleColorMap(-120, 0);
+  //_colorMap = new GrayScaleColorMap(-120, 0);
+  QVector<QColor> colors; colors.reserve(4);
+  colors << Qt::black << Qt::red << Qt::yellow << Qt::white;
+  _colorMap = new LinearColorMap(colors, -60, 0);
 
   // Get notified once a new spectrum is available:
   QObject::connect(_spectrum, SIGNAL(spectrumUpdated()), this, SLOT(_onSpectrumUpdated()));
diff --git a/src/gui/waterfallview.hh b/src/gui/waterfallview.hh
index cc58f81..b6af394 100644
--- a/src/gui/waterfallview.hh
+++ b/src/gui/waterfallview.hh
@@ -52,6 +52,18 @@ public:
   virtual QColor map(const double &value);
 };
 
+/** A linear interpolating color map. */
+class LinearColorMap: public ColorMap {
+public:
+  LinearColorMap(const QVector<QColor> &colors, double min, double max);
+  /** Destructor. */
+  virtual ~LinearColorMap();
+  virtual QColor map(const double &value);
+
+protected:
+  QVector<QColor> _colors;
+};
+
 
 /** A simple waterfall display of the spectrogram. */
 class WaterFallView : public QWidget
diff --git a/src/rtlsource.cc b/src/rtlsource.cc
index 9d9ab5b..72495b2 100644
--- a/src/rtlsource.cc
+++ b/src/rtlsource.cc
@@ -109,6 +109,16 @@ RTLSource::stop() {
   pthread_join(_thread, &p);
 }
 
+size_t
+RTLSource::numDevices() {
+  return rtlsdr_get_device_count();
+}
+
+std::string
+RTLSource::deviceName(size_t idx) {
+  return rtlsdr_get_device_name(idx);
+}
+
 
 void *
 RTLSource::__rtl_srd_parallel_main(void *ctx) {
diff --git a/src/rtlsource.hh b/src/rtlsource.hh
index 3b7db01..bd5da5a 100644
--- a/src/rtlsource.hh
+++ b/src/rtlsource.hh
@@ -55,6 +55,8 @@ public:
   /** Stops the reception. */
   void stop();
 
+  static size_t numDevices();
+  static std::string deviceName(size_t idx);
 
 protected:
   /** Prallel routine to receive some data from the device. */