diff --git a/src/app/commands/cmd_change_color.cpp b/src/app/commands/cmd_change_color.cpp
index 3f431c93a..076bc836b 100644
--- a/src/app/commands/cmd_change_color.cpp
+++ b/src/app/commands/cmd_change_color.cpp
@@ -75,15 +75,20 @@ void ChangeColorCommand::onExecute(Context* context)
       // do nothing
       break;
     case IncrementIndex: {
-      int index = color.getIndex();
-      if (index < get_current_palette()->size()-1)
-        color = app::Color::fromIndex(index+1);
+      const int palSize = get_current_palette()->size();
+      if (palSize >= 1) {
+        // Seems safe to assume getIndex() will return a
+        // positive number, so use truncation modulo.
+        color = app::Color::fromIndex((color.getIndex() + 1) % palSize);
+      }
       break;
     }
     case DecrementIndex: {
-      int index = color.getIndex();
-      if (index > 0)
-        color = app::Color::fromIndex(index-1);
+      const int palSize = get_current_palette()->size();
+      if (palSize >= 1) {
+        // Floor modulo.
+        color = app::Color::fromIndex(((color.getIndex() - 1) % palSize + palSize) % palSize);
+      }
       break;
     }
   }