The united states flag has all these colors and it stands for freedom. In the United states of America police cars have bright red white and blue lights on top of their vehicles, they turn them on when following or chasing someone they believe to have broken the law.
On the french tricolore blue represents the military, red the clergy and white the monarchy, blue being the part of the flag attached to the pole that the flag is put on, meaning that the military holds the state. But there are many other interpretations too.