Possible Clues:

• Regular visitor put somewhat in shade
• Regular shade used outside a little
• Frequent visitor slightly in the shade?
• Regular customer's slightly boring tone
• Frequent visitor sounds surprised at Institute and University in Belgium
• Frequent visitor rather put in shade
• Regular attendant sees a drop in colour
• Visitor frequently wants a short time in shade
• Regular dress for sister, not even used
• Regular held up European organisation note: 'Humbug!'