Because it utilizes two sets of opposites on the colour wheel, this scheme offers the highest contrast possible while maintaining a sense of balance. However, it is also the most difficult scheme to balance successfully.
Use the final color sparingly to provide a tiny spark of contrast. Real-World Examples tetradic colours
This version uses two complementary pairs that are separated by one or two spaces. For example: Red and Green (Pair 1) plus Blue and Orange (Pair 2). Because it utilizes two sets of opposites on