color item icon backgrounds in the UI from visuals.toml

src/ui/MainWindow.cpp

@@ -55,7 +55,7 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir,
     // REQ-UI-BUILD-ICON).
     const QString configDirPath = QString::fromStdString(m_configDir);
     m_itemIcons = std::make_unique<ItemIconCache>(
-        QDir::cleanPath(configDirPath + "/../icons/items"));
+        QDir::cleanPath(configDirPath + "/../icons/items"), &m_visuals);
     m_buildingIcons = std::make_unique<BuildingIconCache>(
         QDir::cleanPath(configDirPath + "/../icons/buildings"));
 
@@ -283,6 +283,9 @@ std::optional<GameConfig> MainWindow::reloadConfig()
         VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
         m_visuals = std::move(newVisuals);
         m_dimOverlay->setDimColor(m_visuals.overlays.modalDim);
+        // The composed item squares carry the colors they were painted with, so they
+        // are dropped for the new ones to take effect (REQ-UI-ITEM-ICON).
+        m_itemIcons->clearPixmapCache();
         return newConfig;
     }
     catch (const std::exception& e)