Related Clues:

• Substance for staining or colouring hair
• Faded yellow -- you won't see all that colour
• A Study in Scarlet might use such regular characters of Doyle's
• Indigo, for instance
• Colourant said to perish
• Artificial colour
• Paintball ammunition
• Why a woman may be blond
• Liquid coloring
• "Does she or doesn't she?" mystery
• It turns pistachios red
• Maraschino cherry feature
• Litmus, for example
• Blend in roots
• Hair application, sometimes