diff --git a/doc/threedvis/src/threedvis/core.clj b/doc/threedvis/src/threedvis/core.clj
index 49b7e4b..09cc6ac 100644
--- a/doc/threedvis/src/threedvis/core.clj
+++ b/doc/threedvis/src/threedvis/core.clj
@@ -5,6 +5,8 @@
 (defn print-scad [shape]
   (spit "threedvis.scad" (write-scad shape)))
 
+(def first-led (atom 1))
+
 (defn led [edge]
   (let [long-leg (cylinder 1.5 100)]
     (union
@@ -19,17 +21,23 @@
             (union
              (translate [0 5 -30] (cylinder 1.5 50))
              (translate [7 5 -60] (rotate (/ pi 4) [0 -1 0] (cylinder 1.5 20))))
-            (translate [14 5 -122] (cylinder 1.5 110))
+            (translate [14 5 -117] (cylinder 1.5 100))
             (rotate (/ pi 6) [0 1 0] (union
                                       (translate [4 -5 -10] (cylinder 1.5 15))
                                       (if (not edge) (translate [4 -54 -17] (rotate (/ pi 2) [1 0 0] long-leg)))))
             (if edge (translate [44 -4 -17] (rotate (/ pi 2) [0 1 0] long-leg)))))))
 
+(defn color-led [endpos]
+  (let [pos (swap! first-led inc)]
+    (if (= 6 pos)
+      (color [1 0 0] (led endpos))
+      (led endpos))))
+
 (defn one-pos [endpos]
  (union
-  (translate [0 0 0] (led endpos))
-  (translate [0 0 100] (led endpos))
-  (translate [0 0 200] (led endpos))))
+  (translate [0 0 0] (color-led endpos))
+  (translate [0 0 100] (color-led endpos))
+  (translate [0 0 200] (color-led endpos))))
 
 (defn one-column []
   (union
diff --git a/doc/threedvis/threedvis.scad b/doc/threedvis/threedvis.scad
index 7d72f52..4eea421 100644
--- a/doc/threedvis/threedvis.scad
+++ b/doc/threedvis/threedvis.scad
@@ -33,8 +33,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -80,8 +80,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -127,8 +127,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -178,8 +178,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -197,45 +197,47 @@ translate ([-100, -100, -100]) {
               }
             }
             translate ([0, 0, 100]) {
-              union () {
-                color ([0.5, 0.5, 2, ]) {
-                  difference () {
+              color ([1, 0, 0, ]) {
+                union () {
+                  color ([0.5, 0.5, 2, ]) {
+                    difference () {
+                      union () {
+                        cylinder (h=20, r=10, center=true);
+                        translate ([0, 0, 10]) {
+                          sphere (r=10, center=true);
+                        }
+                        translate ([0, 0, -8]) {
+                          cylinder (h=4, r=13, center=true);
+                        }
+                      }
+                      translate ([0, 13, -7]) {
+                        cube ([30, 5, 10], center=true);
+                      }
+                    }
+                  }
+                  color ([0.3, 0.3, 0.3, ]) {
                     union () {
-                      cylinder (h=20, r=10, center=true);
-                      translate ([0, 0, 10]) {
-                        sphere (r=10, center=true);
+                      translate ([0, 5, -30]) {
+                        cylinder (h=50, r=1.5, center=true);
                       }
-                      translate ([0, 0, -8]) {
-                        cylinder (h=4, r=13, center=true);
+                      translate ([7, 5, -60]) {
+                        rotate (a=45.0, v=[0, -1, 0]) {
+                          cylinder (h=20, r=1.5, center=true);
+                        }
                       }
                     }
-                    translate ([0, 13, -7]) {
-                      cube ([30, 5, 10], center=true);
+                    translate ([14, 5, -117]) {
+                      cylinder (h=100, r=1.5, center=true);
                     }
-                  }
-                }
-                color ([0.3, 0.3, 0.3, ]) {
-                  union () {
-                    translate ([0, 5, -30]) {
-                      cylinder (h=50, r=1.5, center=true);
-                    }
-                    translate ([7, 5, -60]) {
-                      rotate (a=45.0, v=[0, -1, 0]) {
-                        cylinder (h=20, r=1.5, center=true);
-                      }
-                    }
-                  }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
-                  }
-                  rotate (a=29.999999999999996, v=[0, 1, 0]) {
-                    union () {
-                      translate ([4, -5, -10]) {
-                        cylinder (h=15, r=1.5, center=true);
-                      }
-                      translate ([4, -54, -17]) {
-                        rotate (a=90.0, v=[1, 0, 0]) {
-                          cylinder (h=100, r=1.5, center=true);
+                    rotate (a=29.999999999999996, v=[0, 1, 0]) {
+                      union () {
+                        translate ([4, -5, -10]) {
+                          cylinder (h=15, r=1.5, center=true);
+                        }
+                        translate ([4, -54, -17]) {
+                          rotate (a=90.0, v=[1, 0, 0]) {
+                            cylinder (h=100, r=1.5, center=true);
+                          }
                         }
                       }
                     }
@@ -272,8 +274,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -323,8 +325,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -370,8 +372,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -417,8 +419,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -472,8 +474,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -519,8 +521,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -566,8 +568,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -617,8 +619,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -664,8 +666,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -711,8 +713,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -762,8 +764,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -809,8 +811,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -856,8 +858,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -911,8 +913,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -958,8 +960,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1005,8 +1007,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1056,8 +1058,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1103,8 +1105,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1150,8 +1152,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1201,8 +1203,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1248,8 +1250,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {
@@ -1295,8 +1297,8 @@ translate ([-100, -100, -100]) {
                       }
                     }
                   }
-                  translate ([14, 5, -122]) {
-                    cylinder (h=110, r=1.5, center=true);
+                  translate ([14, 5, -117]) {
+                    cylinder (h=100, r=1.5, center=true);
                   }
                   rotate (a=29.999999999999996, v=[0, 1, 0]) {
                     union () {