The three secondary colors often taught and discussed in art classrooms are those based on paint, which is also a subtractive system. Paint uses red, blue, and yellow as the three primary colors and uses orange, violet, and green as the secondary colors. When combined,
Red and yellow create orange
Red and blue create violet or purple
Blue and yellow create green
They make a pleasing composition because they are analogous on the color wheel meaning they are next to each other on the secondary scale.