diff --git a/include/openmc/plot.h b/include/openmc/plot.h
index d762cad70..48920afad 100644
--- a/include/openmc/plot.h
+++ b/include/openmc/plot.h
@@ -49,6 +49,10 @@ struct RGBColor {
     blue = v[2];
   }
 
+  bool operator ==(const RGBColor& other) {
+    return red == other.red && green == other.green && blue == other.blue;
+  }
+
   // Members
   uint8_t red, green, blue;
 };
diff --git a/src/plot.cpp b/src/plot.cpp
index d53a12805..78b1c6a71 100644
--- a/src/plot.cpp
+++ b/src/plot.cpp
@@ -403,6 +403,10 @@ Plot::set_default_colors(pugi::xml_node plot_node)
 
   for (auto& c : colors_) {
     c = random_color();
+    // make sure we don't interfere with some default colors
+    while (c == RED || c == WHITE) {
+      c = random_color();
+    }
   }
 }