Possible Clues:

• American clutching black gemstone
• Companion leaves the room with preserving agent
• Gascoigne losing his head is a caution
• A doctor, with some hesitation, gives warning
• Traffic signal color
• Brown hue
• Fossil resin used in jewellery
• Predominant colour on Hull City's shirt
• Dispersion of bream indicates caution
• Like the "waves of grain"