Possible Clues:

• On one's last legs
• Faulkner's 'As I Lay ___'
• About to go out
• Like a graying ember
• On the point of death
• Failing on the stage
• Not getting many laughs, as a comedian
• Withering
• Passing on the shade of a change, by the sound of it
• The last thing you'd be doing would be making this just a shade different, by the sound of it