Art. 1 of the 2004 flag law mentions the symbolism of the colors, as patriotic bloodshed, nature’s bounty, and verdure and hope.
In Whitney Smith’s Flags through he Ages and Across the World the red is said to stand for the bravery of the Bolivian soldier, green is the fertility of the land and yellow represents the country’s mineral resources.
In Webster’s Concise Encyclopedia of Flags, 1985: The three horizontal stripes of the Bolivian flag — red, yellow and green — respectively symbolize the gallantry of Bolivian soldiers, the country’s mineral wealth, and the fertility of the land.The meaning of colors on flags is usually given after a flag is adopted; this was probably the case here, as they were derived from earlier flags of Colombia and her liberator, Simon Bolívar.
According to Webster’s Concise Encyclopedia of Flags, 1985, the flag with its present order of stripes was introduced in 1851 but a number of variations had been used since Bolivia gained independence in 1825.
The suyu wiphalas are composed of a 7 × 7 square patchwork in seven colours, arranged diagonally. The precise configuration depends on the particular suyu represented by the emblem. The colour of the longest diagonal line (seven squares) determines which of the four suyus (regions) the flag represents: white for Qullasuyu, yellow for Kuntisuyu, red for Chinchaysuyu, and green for Antisuyu. There is also an alternate pattern for the Wiphala for Antinsuyu. Additionally a Wiphala also exists for Tupac Katari and the Tupac Katari Guerrilla Army.