diff --git a/simgear/scene/tgdb/SGNodeTriangles.hxx b/simgear/scene/tgdb/SGNodeTriangles.hxx
index 128b242d..799240b0 100644
--- a/simgear/scene/tgdb/SGNodeTriangles.hxx
+++ b/simgear/scene/tgdb/SGNodeTriangles.hxx
@@ -267,12 +267,12 @@ public:
                             SGVec2f texCoord = a*t0 + b*t1 + c*t2;
                     
                             // Check this random point against the object mask
-                            // red channel.
+                            // blue channel.
                             osg::Image* img = object_mask->getImage();            
                             unsigned int x = (int) (img->s() * texCoord.x()) % img->s();
                             unsigned int y = (int) (img->t() * texCoord.y()) % img->t();
                     
-                            if (mt_rand(&seed) < img->getColor(x, y).r()) {                
+                            if (mt_rand(&seed) < img->getColor(x, y).b()) {
                                 points.push_back(randomPoint);        
                             }                    
                         } else {      
diff --git a/simgear/scene/tgdb/SGTexturedTriangleBin.hxx b/simgear/scene/tgdb/SGTexturedTriangleBin.hxx
index b39ead0a..bdf33eec 100644
--- a/simgear/scene/tgdb/SGTexturedTriangleBin.hxx
+++ b/simgear/scene/tgdb/SGTexturedTriangleBin.hxx
@@ -192,12 +192,12 @@ public:
           SGVec2f texCoord = a*t0 + b*t1 + c*t2;
           
           // Check this random point against the object mask
-          // red channel.
+          // blue channel.
           osg::Image* img = object_mask->getImage();            
           unsigned int x = (int) (img->s() * texCoord.x()) % img->s();
           unsigned int y = (int) (img->t() * texCoord.y()) % img->t();
           
-          if (mt_rand(&seed) < img->getColor(x, y).r()) {                
+          if (mt_rand(&seed) < img->getColor(x, y).b()) {
             points.push_back(randomPoint);        
           }                    
         } else {