Possible Clues:

• Red mark allowed
• Potential big name actor going around college: time to go red
• Red mark of damage on permit
• Red mark remaining following cut
• Red produced from poor clarets
• Rutgers team color
• Fallen, little evidence of injury?
• Perhaps a miniature mark left after a wound is bloody?
• Lodge housing boy — Holmes's study was in it
• Colour Zeiss perhaps introduced to series