Why do so many countries have the colors red, blue, and white on their flags?

Question

Why do so many countries have the colors red, blue, and white on their flags?

In: Other

Answer 1

because, historically, the three cheapest dyes in for western countries were red, blue and (undyed) white.

so, most nations settled on some combination of those three colours, plus sometimes another colour if that was locally cheap as well.