there is no meaning to the Colombian flag. But there are theories behind what it might mean. Like yellow symbolizes sovereignty and justice. Blue is for nobility, loyalty, and vigilance. The red stands for valor, honor, generosity, and victory. This is just the theories behind it.
Philadelphia's flag is made up primarily of blue and yellow, which were adopted to commemorate Philadelphia's Swedish origins. Sweden originally colonized Philadelphia, and the colors of the flag were adopted in 1874.