Translation:The flag of the Netherlands has three colors.
The flag from the Netherlands = De vlag uit Nederland
Also have a read through this: http://esl.about.com/od/grammarstructures/a/Difference-Between-Of-And-From.htm
It's actually the first European tricolour. All the tricolour flags you can think of can trace their origins back to it. (by tricolour, I mean three coloured stripes of equal size following the design of the Dutch flag, not just any flag that happens to have three colours )