What color on the corps colours signifies an intimate connection with the Royal Navy?

The color that signifies an intimate connection with the Royal Navy is blue. This hue has a historical significance reflecting the deep-rooted relationship between the Royal Marines and the Navy, as the Royal Marines are a part of the naval service. The blue symbolizes this affiliation and aligns with naval traditions and identity. It represents the operational environment of the Royal Marines, who often work closely with naval forces.

Other colors like Old Gold, Infantry Green, and Red have their own meanings within the context of military history or other branches of service, but it is blue that specifically denotes the bond with the Royal Navy, highlighting the integrated nature of maritime operations conducted by the Royal Marines alongside their naval counterparts.