Why does Colombia's flag have the yellow stripe bigger than the blue and the red?

The current flag of Colombia was officially adopted on December 17, 1819.

The flag features three horizontal bands of yellow (double-width), blue and red. Colors of the flag are commonly interpreted in two ways:

One version indicates that the yellow symbolizes sovereignty and justice, blue as loyalty and vigilance, and red represents the valor shown and the victory achieved during the battles for independence from Spain.

A very popular children's song claims that yellow represents the gold Colombia once owned until the arrival of the Spanish, blue indicates the country's contact with two oceans and red represents the blood that Colombians spent in their struggle for independence from Spain.
http://worldatlas.com/webimage/flags/countrys/samerica/colombia.htm

Yeah, but why is yellow bigger?