diff --git a/Apps/Tuto/tuto5.cpp b/Apps/Tuto/tuto5.cpp
index e7d9a5f472fdb98370c0fe8e1c66a4d38825138b..525a30c0392df81436d85f9e1353a16ac8dbcbf9 100644
--- a/Apps/Tuto/tuto5.cpp
+++ b/Apps/Tuto/tuto5.cpp
@@ -108,9 +108,26 @@ void myGlutWin::myRedraw(void)
 	glTranslatef(-gPosObj[0],-gPosObj[1],-gPosObj[2]);
 
 
+
 	glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
 	glDisable(GL_LIGHTING);
 
+	glLineWidth(3.0);
+	glBegin(GL_LINES);
+	glColor3f(1.,0.,0.);
+	glVertex3f(0.0,0.0,0.0);
+	glVertex3f(1.0,0.0,0.0);
+
+	glColor3f(0.,1.,0.);
+	glVertex3f(0.0,0.0,0.0);
+	glVertex3f(0.0,1.0,0.0);
+
+	glColor3f(0.,0.,1.);
+	glVertex3f(0.0,0.0,0.0);
+	glVertex3f(0.0,0.0,1.0);
+
+	glEnd();
+
 	glColor3f(0.0f,1.0f,.0f);
 	m_render->draw(Algo::Render::VBO::POINTS);
 
@@ -187,6 +204,7 @@ void myGlutWin::myKeyboard(unsigned char keycode, int x, int y)
 
         	}
         		break;
+
         	case 'x':
         	{
         		// push/pop color is only needed for dart coloring conservation
@@ -203,22 +221,23 @@ void myGlutWin::myKeyboard(unsigned char keycode, int x, int y)
         		glTranslatef(-gPosObj[0],-gPosObj[1],-gPosObj[2]);
         		//pick
         		Dart d = m_render_topo->picking(x,H-y);
+
         		glPopMatrix();
 
         		m_render_topo->popColors();
 
-        		if (d != Dart::nil())
+         		if (d != Dart::nil())
         		{
+        			m_render_topo->setDartColor(d,1.0,0.0,0.0);
         			redraw();
         			std::stringstream ss;
         			ss << "Pick dart:" << d << std::endl<<"pos="<< position[d];
         			glColor3f(1.,1.,0.);
         			printString2D(x+12,y+22,ss.str());
         			glutSwapBuffers();
-//        			std::cout << "Pick dart:" << d << " position= "<< position[d] << std::endl;
-        			std::cout << "Pick dart:" << d << std::endl;
+        			std::cout << "Pick dart:" << d << " pos= "<< position[d] << std::endl;
         		}
-        		// in console:
+
 
         		break;
         	}
@@ -427,6 +446,8 @@ int main(int argc, char **argv)
 		nb = atoi(argv[1]);
 	dglobal = prim.hexaGrid_topo(nb,nb,nb);
 	prim.embedHexaGrid(1.0f,1.0f,1.0f);
+
+
 //	Geom::Matrix44f mat;
 //	mat.identity();
 //	Geom::scale(2.0f, 2.0f,2.0f,mat);
diff --git a/include/Algo/Render/topo3_vboRender.h b/include/Algo/Render/topo3_vboRender.h
index c771cd2bbcd2833b95662b22e9780ff919ea08cf..bb8b1442cea7fb1f2845fcc3b5d40fb5e5a60487 100644
--- a/include/Algo/Render/topo3_vboRender.h
+++ b/include/Algo/Render/topo3_vboRender.h
@@ -118,6 +118,11 @@ protected:
 
 
 public:
+
+	Dart colToDart(float* color);
+
+	void dartToCol(Dart d, float& r, float& g, float& b);
+
 	/**
 	* Constructor
 	* @param map the map to draw
diff --git a/include/Algo/Render/topo3_vboRender.hpp b/include/Algo/Render/topo3_vboRender.hpp
index 7bde19ad69440df173f6d860e22137a9536de5ae..9852b75ec7948030e9e069206756e816a12aadfa 100644
--- a/include/Algo/Render/topo3_vboRender.hpp
+++ b/include/Algo/Render/topo3_vboRender.hpp
@@ -905,21 +905,15 @@ void topo3_VBORender::setDartsIdColor(typename PFP::MAP& map, const FunctorSelec
 		{
 			if (good(d))
 			{
-				unsigned int lab = d.index + 1; // add one to avoid picking the black of screen
-
-				float r = float(lab%256) / 256.0f; lab = lab/256;
-				float g = float(lab%256) / 256.0f; lab = lab/256;
-				float b = float(lab%256) / 256.0f; lab = lab/256;
-
-				if (lab!=0)
-					std::cerr << "Error picking color, too many darts"<< std::endl;
-
-				*colorBuffer++ = r;
-				*colorBuffer++ = g;
-				*colorBuffer++ = b;
-				*colorBuffer++ = r;
-				*colorBuffer++ = g;
-				*colorBuffer++ = b;
+				float r,g,b;
+				dartToCol(d, r,g,b);
+				float* local = colorBuffer+3*m_attIndex[d]; // get the right position in VBO
+				*local++ = r;
+				*local++ = g;
+				*local++ = b;
+				*local++ = r;
+				*local++ = g;
+				*local++ = b;
 
 				nb++;
 			}
diff --git a/src/Algo/Render/topo3_vboRender.cpp b/src/Algo/Render/topo3_vboRender.cpp
index 730c5431bf37f5ae75e462f384d4d2dea46983ec..f8f35bbd4d2e03e6b73cb422077a1168a3924570 100644
--- a/src/Algo/Render/topo3_vboRender.cpp
+++ b/src/Algo/Render/topo3_vboRender.cpp
@@ -98,7 +98,7 @@ void topo3_VBORender::setAllDartsColor(float r, float g, float b)
 
 void topo3_VBORender::drawDarts()
 {
-	glColor3f(1.0f,1.0f,1.0f);
+//	glColor3f(1.0f,1.0f,1.0f);
 	glLineWidth(m_topo_dart_width);
 	glPointSize(2.0f*m_topo_dart_width);
 
@@ -214,6 +214,32 @@ void topo3_VBORender::popColors()
 }
 
 
+Dart topo3_VBORender::colToDart(float* color)
+{
+	unsigned int r = (unsigned int)(color[0]*255.0f);
+	unsigned int g = (unsigned int)(color[1]*255.0f);
+	unsigned int b = (unsigned int)(color[2]*255.0f);
+
+	unsigned int id = r + 255*g +255*255*b;
+
+	if (id==0)
+		return Dart::nil();
+	return  Dart(id-1);
+
+}
+
+void topo3_VBORender::dartToCol(Dart d, float& r, float& g, float& b)
+{
+	unsigned int lab = d.index + 1; // add one to avoid picking the black of screen
+
+	r = float(lab%255) / 255.0f; lab = lab/255;
+	g = float(lab%255) / 255.0f; lab = lab/255;
+	b = float(lab%255) / 255.0f; lab = lab/255;
+	if (lab!=0)
+		std::cerr << "Error picking color, too many darts"<< std::endl;
+}
+
+
 Dart topo3_VBORender::picking(unsigned int x, unsigned int y)
 {
 	//more easy picking for
@@ -241,17 +267,7 @@ Dart topo3_VBORender::picking(unsigned int x, unsigned int y)
 
 	glClearColor(cc[0], cc[1], cc[2], cc[3]);
 
-	// compute dart index:
-	unsigned int r = (unsigned int)(color[0]*255.0f);
-	unsigned int g = (unsigned int)(color[1]*255.0f);
-	unsigned int b = (unsigned int)(color[2]*255.0f);
-
-	unsigned int id = r + 256*g +256*256*b;
-
-	if (id == 0)
-		return Dart::nil();
-
-	return Dart(id-1); // -1 because we draw +1
+	return colToDart(color);
 }