Issued by South Vietnam (Việt-Nam Cộng-Hòa) in 1957, this commemorative pair marks the 9th Colombo Plan Conference held in Saigon, an important post-war regional development meeting.
The design features a symbolic conference emblem with maritime and industrial elements, reflecting economic cooperation and planning for prosperity in Asia-Pacific nations.
Printed in contrasting green (3₫) and rose-red (0.50₫), the stamps show clean typography and strong mid-century graphic style typical of early Republic of Vietnam issues.
This set is significant for collectors of Asian political history, international cooperation, and early South Vietnam postal issues.
A desirable short set from the 1950s, often sought in fine condition due to its historical relevance.