refactor color iter logic

Author: AlexWilkinsonnn

larpandoracontent/LArMonitoring/VisualMonitoringAlgorithm.cc

@@ -218,16 +218,18 @@ void VisualMonitoringAlgorithm::VisualizeCaloHitList(const std::string &listName
         volIdToCaloHits[volId].push_back(pCaloHit);
     }
 
-    [[maybe_unused]] int colorIter{0};
+#ifdef MONITORING
+    Color colorIter{BLACK};
     for (const auto &[volId, caloHitListPartition] : volIdToCaloHits)
     {
         const std::string label{(listName.empty() ? "CurrentCaloHits" : listName) +
             ", volId ("  + std::to_string(volId.first) + ", " + std::to_string(volId.second) + ")"};
-        PANDORA_MONITORING_API(VisualizeCaloHits(this->GetPandora(), &caloHitListPartition, label.c_str(),
-            static_cast<Color>(++colorIter) < AUTO          ? static_cast<Color>(colorIter)
-                : (colorIter % static_cast<int>(AUTO)) == 0 ? static_cast<Color>(++colorIter % static_cast<int>(AUTO))
-                                                            : static_cast<Color>(colorIter % static_cast<int>(AUTO))));
+        PANDORA_MONITORING_API(VisualizeCaloHits(this->GetPandora(), &caloHitListPartition, label.c_str(), colorIter));
+        colorIter = static_cast<Color>(static_cast<int>(colorIter) + 1);
+        if (colorIter >= AUTO)
+            colorIter = BLACK;
     }
+#endif
 }
 
 //------------------------------------------------------------------------------------------------------------------------------------------