Technically, the red dash on your Downloads folder should not be there. However, you should also not have any problems with the folder. Optionally, it can be easily and quickly fixed by following the directions below.
1. Click on the Downloads folder to bring up the Open in Finder menu.
2. Click on the Open in Finder icon to bring up the window.
3. Select the Downloads folder, then go to the File menu and select Get Info.
4. In the Info window, check, then uncheck the Locked checkbox to reset it. Leave the folder unlocked.
5. Close the Info window and the red dash on your Downloads folder should now be gone.