This type of color scheme is what you are using if you are painting with pastels on a colored paper. Every color in the painting picks up a small amount of the hue from the paper. That's why the use of underpaintings are so effective.
But another way of achieving this, especially in watercolor - where you can't really use an underpainting - is to pick one color. In the painting above I've chosen a cobalt blue. Then for every other color I use in the scheme I've added anywhere from a touch to a large amount of cobalt. So my yellows become more to the green side, my green is blued, my reds become more violet and the oranges of the fields become more siennas and nature toned.
And now - the movie!! I saw an absolutely fantastic movie this weekend and it was right to the subject of something we've discussed in class. Is tracing, gridding, projecting, i.e. copying legal? Not that it answered the question but it did raise some very interesting questions as well provide an absolutely incredible story. The name is Tim's Vermeer and it's at the Fleur. If you get the chance, see it and we'll discuss it in class. I will say I am in more awe than ever of Vermeer and of Tim.