No, that applies to the whole of the Netherlands, not just Holland. The reason for our infatuation with the colour is because our royal family is the House of Orange-Nassau. That's why e.g. the colour of the national football team is orange.

But I think I noticed it more because it takes up about a quarter of the vertical size of my screen on the YouTube home page, and has gigantic text on it (I guess the ad is less noticeable if you can't actually read Japanese?).