Index: lnt/server/ui/views.py
===================================================================
--- lnt/server/ui/views.py
+++ lnt/server/ui/views.py
@@ -930,8 +930,8 @@
         # Determine the base plot color.
         col = list(util.makeDarkColor(float(i) / num_plots))
         url = "/".join([str(machine.id), str(test.id), str(field_index)])
-        legend.append(LegendItem(machine, test.name, field.name, tuple(col),
-                                 url))
+        legend.append(LegendItem(machine, test.name, field.name,
+                                 tuple(map(int, col)), url))
 
         # Load all the field values for this test on the same machine.
         #
@@ -985,7 +985,7 @@
             # Make a color closer to the sample than its neighbour.
             color_offset = float(baseline_id) / num_baselines / 2
             my_color = (i + color_offset) / num_plots
-            dark_col = list(util.makeDarkerColor(my_color))
+            dark_col = list(map(int, util.makeDarkerColor(my_color)))
             str_dark_col = util.toColorString(dark_col)
             baseline_plots.append({
                 'color': str_dark_col,