A Vietnamese Festival Flag (fig.), known in Vietnamese as Co Ngu Hanh, i.e. ‘Five Elements Flag’. It consists of concentric squares in various colours, framed by a deeply indented border that is usually red –yet sometimes dark blue– in colour, and with a thin white outer rim.

The colours used in the flag symbolize the corresponding colours of the Five Elements according to ancient Chinese philosophy, though black is replaced by blue and unrelated colours are sometimes used. The colours may appear in any order, may include the colour red or blue twice, and flags often number less than four concentric squares, not counting the central field.