Possible Clues:

• Red mark allowed
• Potential big name actor going around college: time to go red
• Red mark of damage on permit
• Sign of wound, granted, displays colour of blood
• Mark of wound allowed to be red
• Ruined castle inhabited by king's shade
• Rutgers team color
• New cartels in the red?
• Perhaps a miniature mark left after a wound is bloody?
• Lodge housing boy — Holmes's study was in it