Successfully complete the indicated challenge with any character to unlock the 
corresponding color. Note: Once a color is unlocked, it can be used by any 
character.
  Color 3: Time Attack (Normal) 1 
  Color 4: Survival (Normal) 1 
  Color 5: Time Attack (Normal) 6 
  Color 6: Survival (Normal) 6 
  Color 7: Time Attack (Normal) 11 
  Color 8: Survival (Normal) 11 
  Color 9: Time Attack (Normal) 16 
  Color 10: Survival (Normal) 16