diff --git a/src/painter.py b/src/painter.py
index 3f502fe..264165e 100644
--- a/src/painter.py
+++ b/src/painter.py
@@ -176,39 +176,42 @@ class Painter(Widget):
             while self.pos_tocoord_x(xx)<self.width:
                 yy=pos.y
                 while self.pos_tocoord_y(yy)<self.height:
-                    if self.is_in_voronoi(xx,yy,particle):
-                        self.draw_voronoi_site(xx,yy,particle.color)
+                    self.draw_voronoi_site(xx,yy,particle.color,self.is_in_voronoi(xx,yy,particle))
                     yy+=self.lattice.spacing
                 yy=pos.y-self.lattice.spacing
                 while self.pos_tocoord_y(yy)>0:
-                    if self.is_in_voronoi(xx,yy,particle):
-                        self.draw_voronoi_site(xx,yy,particle.color)
+                    self.draw_voronoi_site(xx,yy,particle.color,self.is_in_voronoi(xx,yy,particle))
                     yy-=self.lattice.spacing
                 xx+=self.lattice.spacing
             xx=pos.x-self.lattice.spacing
             while self.pos_tocoord_x(xx)>0:
                 yy=pos.y
                 while self.pos_tocoord_y(yy)<self.height:
-                    if self.is_in_voronoi(xx,yy,particle):
-                        self.draw_voronoi_site(xx,yy,particle.color)
+                    self.draw_voronoi_site(xx,yy,particle.color,self.is_in_voronoi(xx,yy,particle))
                     yy+=self.lattice.spacing
                 yy=pos.y-self.lattice.spacing
                 while self.pos_tocoord_y(yy)>0:
-                    if self.is_in_voronoi(xx,yy,particle):
-                        self.draw_voronoi_site(xx,yy,particle.color)
+                    self.draw_voronoi_site(xx,yy,particle.color,self.is_in_voronoi(xx,yy,particle))
                     yy-=self.lattice.spacing
                 xx-=self.lattice.spacing
     # check whether a site is in the Voronoi cell of a particle
     def is_in_voronoi(self,x,y,particle):
         d_to_particle=self.lattice.distance_to_particle(x,y,particle)
+        # count how many are in voronoi cell
+        count=1
         # TODO: start  with a particle that is close to x,y
         for q in self.particles:
-            if q!=particle and self.lattice.distance_to_particle(x,y,q)<d_to_particle:
-                return False
-        return True
+            dd=self.lattice.distance_to_particle(x,y,q)
+            if q!=particle and dd<d_to_particle:
+                return 0
+            if dd==d_to_particle:
+                count+=1
+        return count
     # draw a site in a Voronoi cell
-    def draw_voronoi_site(self,x,y,color):
-        Color(color[0],color[1],color[2],0.75)
+    def draw_voronoi_site(self,x,y,color,count):
+        if count==0:
+            return
+        Color(color[0],color[1],color[2],1-count*0.1)
         Rectangle(pos=(self.pos_tocoord_x(x-0.5),self.pos_tocoord_y(y-0.5)),size=(self.base_size,self.base_size))