Index: qgsgraduatedsymboldialog.cpp
===================================================================
--- qgsgraduatedsymboldialog.cpp	(revision 7281)
+++ qgsgraduatedsymboldialog.cpp	(working copy)
@@ -224,6 +224,33 @@
 	mVectorLayer->setRenderer(renderer);
 }
 
+QColor QgsGraduatedSymbolDialog::getColorFromRamp(QString ramp, int step, int totalSteps)
+{
+  QColor color;
+
+  /* To do:
+     Grab the ramp by name from a file or ramp registry
+       and apply determine the color for the given step.
+     Ideally there would be two types of ramps:
+       - discrete colors: the number of steps would have to match totalSteps
+       - continuous colors: (eg grass or gmt ramps) would need to code a method
+          for determining an RGB color for any point along the continuum
+     Color ramps should be plugin-able; should be defined in a simple text file format
+       and read from a directory where users can add their own ramps. 
+  */
+
+  if (step == 0)
+  {
+    color = QColor(0,255,0);
+  } 
+  else
+  {
+    color = QColor(0,255-((255/totalSteps)*step+1),((255/totalSteps)*step+1));    
+  } 
+
+  return color;
+}
+
 void QgsGraduatedSymbolDialog::adjustClassification()
 {
     mClassListWidget->clear();
@@ -275,32 +302,22 @@
 	QPen pen;
 	QBrush brush;
 
+
 	//apply a nice color range from red to green as default
-	//todo: make other color ranges available
-	if (i == 0)
-	  {
-	    if (m_type == QGis::Line)
-	      {
-		pen.setColor(QColor(255, 0, 0));
-	      } 
-	    else                //point or polygon
-	      {
-		brush.setColor(QColor(255, 0, 0));
-		pen.setColor(Qt::black);
-	      }
-	  } 
-	else
-	  {
-	    if (m_type == QGis::Line)
-	      {
-		pen.setColor(QColor(255 - (255 / numberofclassesspinbox->value() * (i+1)), 255 / numberofclassesspinbox->value() * (i+1), 0));
-	      } 
-	    else                //point or polygon
-	      {
-		brush.setColor(QColor(255 - (255 / numberofclassesspinbox->value() * (i+1)), 255 / numberofclassesspinbox->value() * (i+1), 0));  
-		pen.setColor(Qt::black);
-	      }
-	  }
+        // todo: These color ramps should come from a dropdown list 
+        QString ramp;
+        ramp = "red_to_green";
+        
+        if (m_type == QGis::Line)
+	{
+	  pen.setColor(getColorFromRamp(ramp,i, numberofclassesspinbox->value()));
+	} 
+	else //point or polygon
+	{
+	  brush.setColor(getColorFromRamp(ramp,i, numberofclassesspinbox->value()));
+	  pen.setColor(Qt::black);
+	}
+	
 	pen.setWidth(1);
 	brush.setStyle(Qt::SolidPattern);
 	symbol->setPen(pen);
Index: qgsgraduatedsymboldialog.h
===================================================================
--- qgsgraduatedsymboldialog.h	(revision 7281)
+++ qgsgraduatedsymboldialog.h	(working copy)
@@ -39,6 +39,8 @@
  protected slots:
      /**Changes only the number of classes*/
      void adjustNumberOfClasses();
+     /**Gets the color value along a specified ramp**/
+     QColor getColorFromRamp(QString ramp, int step, int totalSteps);
      /**Sets a new classification field and a new classification mode*/
      void adjustClassification();
      /**Changes the display of the single symbol dialog*/