MARINE CORPS BASE QUANTICO, Va. – Sgt. Alex Tucker, base color sergeant, Ceremonial Platoon, holds onto a sheathed American flag before a practice session. Tucker, a Philadelphia native, is Quantico’s 13th color sergeant since 1999. - MARINE CORPS BASE QUANTICO, Va. – Sgt. Alex Tucker, base color sergeant, Ceremonial Platoon, holds onto a sheathed American flag before a practice session. Tucker, a Philadelphia native, is Quantico’s 13th color sergeant since 1999.