Related Clues:

• Cover-up of a sort
• Salon color
• Turn blue, maybe
• Amber or umber
• Henna, for one
• Litmus, essentially
• Stuff in a robber-foiling pack
• It may be red
• It changes locks
• Salon application
• Burgundy, for one
• Food additive
• Textile company purchase
• Indigo, for one
• Turn red, perhaps