fix: changing colormap for second volume in fusion viewport (#4746)

extensions/cornerstone/src/commandsModule.ts

@@ -756,7 +756,12 @@ function commandsModule({
           displaySetInstanceUID = viewports.get(viewportId)?.displaySetInstanceUIDs[0];
         }
 
-        const volumeId = viewport.getVolumeId();
+        // ToDo: Find a better way of obtaining the volumeId that corresponds to the displaySetInstanceUID
+        const volumeId =
+          viewport
+            .getAllVolumeIds()
+            .find((_volumeId: string) => _volumeId.includes(displaySetInstanceUID)) ??
+          viewport.getVolumeId();
         viewport.setProperties({ colormap }, volumeId);
       }