Possible Clues:

• Colours
• With age one may give vent to cries of pain
• Gets a shade old
• Lumberjacks initially look to cut trees in shades of autumn?
• Plant disease
• Becomes jaundiced
• Non-whites trapped by shells from batteries?
• Turns lurid, perhaps, as broadsheet influenced by The Sun does?
• Daffodil and primrose, say, almost entirely grown facing north at bottom of yard
• Field swirls with blues and other colours