diff --git a/crystal.cpp b/crystal.cpp
index a1612187..9caedaf3 100644
--- a/crystal.cpp
+++ b/crystal.cpp
@@ -687,6 +687,11 @@ EX color_t colorize(cell *c, char whichCanvas) {
       return res;
       }
       
+    case '/': {
+      int s = ico[1] + ico[2] + ico[3] + ico[0];
+      if(s > 0) return 0x1FF20FF;
+      else if (s < -2) return 0x1C0C0C0;
+      }
     }
   return res;
   }
diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index 477372ce..2fe57c2b 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -774,6 +774,7 @@ EX namespace nilv {
     { point31(0,0,0.5), point31(-0.5,0.5,0.25), point31(-0.5,-0.5,0.75), point31(0,0,0.5), point31(-0.5,-0.5,0.75), point31(-0.5,-0.5,0.5), point31(0,0,0.5), point31(-0.5,-0.5,0.5), point31(0.5,-0.5,0.5), point31(0,0,0.5), point31(0.5,-0.5,0.5), point31(0.5,-0.5,0.25), point31(0,0,0.5), point31(0.5,-0.5,0.25), point31(0.5,0.5,0.75), point31(0,0,0.5), point31(0.5,0.5,0.75), point31(0.5,0.5,0.5), point31(0,0,0.5), point31(0.5,0.5,0.5), point31(-0.5,0.5,0.5), point31(0,0,0.5), point31(-0.5,0.5,0.5), point31(-0.5,0.5,0.25), },
     }};
 
+  EX int zgmod(int a, int b) { return b ? a%b : a; }
 
   array<int,3> nilperiod, nilperiod_edit;
   
@@ -805,7 +806,7 @@ EX namespace nilv {
     heptagon *create_step(heptagon *parent, int d) override {
       auto p = coords[parent];
       auto q = p * movevectors[d];
-      for(int a=0; a<3; a++) if(nilperiod[a]) q[a] = gmod(q[a], nilperiod[a]);
+      for(int a=0; a<3; a++) q[a] = zgmod(q[a], nilperiod[a]);
       auto child = get_at(q);
       parent->c.connect(d, child, (d + nilv_S7/2) % nilv_S7, false);
       return child;
@@ -857,6 +858,27 @@ EX namespace nilv {
     return nisot::translate(s0) * formula_exp(h * x);
     }
 
+EX color_t colorize(cell *c, char whichCanvas) {
+  mvec at = ((hrmap_nil*)currentmap)->coords[c->master];
+  color_t res = 0;
+  
+  auto setres = [&] (int z, color_t which) {
+    if(zgmod(at[2] - z, nilperiod[2]) == 0) res = which;
+    if(zgmod(at[2] - z-1, nilperiod[2]) == 0) res = which;
+    };
+
+  if(at[1] == 0 && at[0] >=0 && at[0] < 4)
+    setres(-at[0], gradient(0x1FF0000, 0x10000FF, 0, at[0], 4));
+  else if(at[0] == 4 && at[1] >= 0 && at[1] < 4)
+    setres(at[1]*3-4, gradient(0x10000FF, 0x100FF00, 0, at[1], 4));
+  else if(at[1] == 4 && at[0] >= 0 && at[0] <= 4)
+    setres(4+at[0], gradient(0x100FF00, 0x1FFFF00, 4, at[0], 0));
+  else if(at[0] == 0 && at[1] >= 0 && at[1] <= 4)
+    setres(at[1], gradient(0x1FFFF00, 0x1FF0000, 4, at[1], 0));
+  
+  return res;
+  }
+
 EX void prepare_niltorus3() {
   nilperiod_edit = nilperiod;
   }
diff --git a/pattern2.cpp b/pattern2.cpp
index 1d9ef8b3..b9f04b00 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -1540,8 +1540,11 @@ EX namespace patterns {
     if(i != -1) return i;
     switch(whichCanvas) {
       #if CAP_CRYSTAL
-      case 'K': case '#': case '=': case 'O':
-        return crystal::colorize(c, whichCanvas);
+      case 'K': case '#': case '=': case 'O': case '/':
+        if(nil)
+          return nilv::colorize(c, whichCanvas);
+        else
+          return crystal::colorize(c, whichCanvas);
       #endif
       case 'A':
         #if CAP_ARCM
@@ -1702,6 +1705,10 @@ EX namespace patterns {
       dialog::addSelItem(XLAT("Cage"), "Crystal", '#');
       dialog::addSelItem(XLAT("Hyperplanes"), "Crystal", '=');
       dialog::addSelItem(XLAT("Honeycomb"), "Crystal", 'O');
+      dialog::addSelItem(XLAT("Diagonal"), "Crystal", '/');
+      }
+    if(nil) {
+      dialog::addSelItem(XLAT("Penrose staircase"), "Nil", '/');
       }
 
     dialog::addSelItem(XLAT("sides"), "sides", 'B');