Rank insignia in the French army depend on whether the soldier belongs to an "infantry" or "cavalry" unit. Sleeves are emblazoned with marks denoting either the infantry or the cavalry: In the infantry the main insignia colour is gold, but in the cavalry the main insignia colour is silver/white. However, the artillery uses gold as the main colour, despite being a cavalry branch, and spahis use gold as the main colour despite being part of the cavalry, a division representing the armored cavalry.
Foot arms: Infantry, Naval troops, Foreign Legion, Engineering, etc.
Horse arms: Armoured Cavalry arm, Train, Artillery, Maintenance and Logistics.
A famous example would be Philippe Pétain, who became famous as Maréchal Pétain, Chief of State of the Vichy France regime and retained his title even after his trial and imprisonment and after he was stripped of other positions and titles.