Related Rule
Ecuador
Practice Relating to Rule 63. Use of Flags or Military Emblems, Insignia or Uniforms of Neutral or Other States Not Party to the Conflict
Ecuador’s Naval Manual (1989) states:
At Sea. Under the customary international law of naval warfare, it is permissible for a belligerent warship to fly false colours and disguise its outward appearance in other ways in order to deceive the enemy into believing the vessel is of neutral nationality or is other than a warship. However, it is unlawful for a warship to go into action without first showing her true colours. Use of neutral flags, insignia, or uniforms during an actual armed engagement at sea is, therefore, forbidden.
In the Air. Use in combat of false or deceptive markings to disguise belligerent military aircraft as being of neutral nationality is prohibited.
On Land. The law of armed conflict applicable to land warfare has no rule of law analogous to that which permits belligerent warships to display neutral colours.
Belligerents engaged in armed conflict on land are not permitted to use the flags, insignia, or uniforms of a neutral nation to deceive the enemy. 
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, § 12.3.