Possible Clues:

• Military clothing
• Dull brown
• Uniform choice
• Can't start the army vehicle without it, by the sound of it
• Brownish-yellow starter's much talked about
• Type of casual pants
• Military uniform cloth - colour
• Yellowish brown colour
• The British might need just a shade of this to get into army transport, by the sound of it
• Camouflage colour