diff --git a/scripts/viz.py b/scripts/viz.py
index 09d7d86dd33..09217d0c405 100755
--- a/scripts/viz.py
+++ b/scripts/viz.py
@@ -2,10 +2,17 @@
 """Visualize an LBANN model's layer graph and save to file."""
 
 import argparse
+import random
 import re
 import graphviz
-import google.protobuf.text_format
 from lbann import lbann_pb2, layers_pb2
+from lbann.proto import serialize
+
+# Pastel rainbow (slightly shuffled) from colorkit.co
+palette = [
+    '#ffffff', '#a0c4ff', '#ffadad', '#fdffb6', '#caffbf', '#9bf6ff',
+    '#bdb2ff', '#ffc6ff', '#ffd6a5'
+]
 
 # Parse command-line arguments
 parser = argparse.ArgumentParser(
@@ -17,14 +24,14 @@
 parser.add_argument('output',
                     action='store',
                     nargs='?',
-                    default='graph.pdf',
+                    default='graph.dot',
                     type=str,
-                    help='output file (default: graph.pdf)')
+                    help='output file (default: graph.dot)')
 parser.add_argument('--file-format',
                     action='store',
-                    default='pdf',
+                    default='dot',
                     type=str,
-                    help='output file format (default: pdf)',
+                    help='output file format (default: dot)',
                     metavar='FORMAT')
 parser.add_argument('--label-format',
                     action='store',
@@ -39,6 +46,10 @@
                     type=str,
                     help='Graphviz visualization scheme (default: dot)',
                     metavar='ENGINE')
+parser.add_argument('--color-cross-grid',
+                    action='store_true',
+                    default=False,
+                    help='Highlight cross-grid edges')
 args = parser.parse_args()
 
 # Strip extension from filename
@@ -51,9 +62,7 @@
 label_format = re.sub(r' |-|_', '', args.label_format.lower())
 
 # Read prototext file
-proto = lbann_pb2.LbannPB()
-with open(args.input, 'r') as f:
-    google.protobuf.text_format.Merge(f.read(), proto)
+proto = serialize.generic_load(args.input)
 model = proto.model
 
 # Construct graphviz graph
@@ -62,29 +71,36 @@
                          engine=args.graphviz_engine)
 graph.attr('node', shape='rect')
 
+layer_to_grid_tag = {}
+
 # Construct nodes in layer graph
 layer_types = (set(layers_pb2.Layer.DESCRIPTOR.fields_by_name.keys()) - set([
     'name', 'parents', 'children', 'datatype', 'data_layout',
     'device_allocation', 'weights', 'freeze', 'hint_layer', 'top', 'bottom',
-    'type', 'motif_layer'
+    'type', 'motif_layer', 'parallel_strategy', 'grid_tag'
 ]))
 for l in model.layer:
 
     # Determine layer type
-    type = ''
+    ltype = ''
     for _type in layer_types:
         if l.HasField(_type):
-            type = getattr(l, _type).DESCRIPTOR.name
+            ltype = getattr(l, _type).DESCRIPTOR.name
             break
 
+    # If operator layer, use operator type
+    if ltype == 'OperatorLayer':
+        url = l.operator_layer.ops[0].parameters.type_url
+        ltype = url[url.rfind('.') + 1:]
+
     # Construct node label
     label = ''
     if label_format == 'nameonly':
         label = l.name
     elif label_format == 'typeonly':
-        label = type
+        label = ltype
     elif label_format == 'typeandname':
-        label = '<{0}<br/>{1}>'.format(type, l.name)
+        label = '<{0}<br/>{1}>'.format(ltype, l.name)
     elif label_format == 'full':
         label = '<'
         for (index, line) in enumerate(str(l).strip().split('\n')):
@@ -94,14 +110,36 @@
         label += '>'
 
     # Add layer as layer graph node
-    graph.node(l.name, label=label)
+    tag = l.grid_tag.value
+    layer_to_grid_tag[l.name] = tag
+    attrs = {}
+    if tag != 0:
+        attrs = dict(style='filled', fillcolor=palette[tag % len(palette)])
+    graph.node(l.name, label=label, **attrs)
 
 # Add parent/child relationships as layer graph edges
 edges = set()
+cross_grid_edges = set()
 for l in model.layer:
-    edges.update([(p, l.name) for p in l.parents.split()])
-    edges.update([(l.name, c) for c in l.children.split()])
+    tag = layer_to_grid_tag[l.name]
+    for p in l.parents:
+        if tag != layer_to_grid_tag[p]:
+            cross_grid_edges.add((p, l.name))
+        else:
+            edges.add((p, l.name))
+
+    for c in l.children:
+        if tag != layer_to_grid_tag[c]:
+            cross_grid_edges.add((l.name, c))
+        else:
+            edges.add((l.name, c))
+
 graph.edges(edges)
+if args.color_cross_grid:
+    for u, v in cross_grid_edges:
+        graph.edge(u, v, color='red')
+else:
+    graph.edges(cross_grid_edges)
 
 # Save to file
 graph.render(filename=filename, cleanup=True, format=file_format)