Using jeans for a Tetrad color scheme also works very well in a casual setting.
Using dark or neutral colors work best when using a Tetrad color scheme in a suit for a professional setting. It can be very tricky to put together. Tip: When putting together a suit, it is okay to use a white shirt as a filler color.
This example of a Tetrad color scheme is suitable for a party setting. Tip: Bright colors often seen as unprofessional.
Triad colors are equally spaced on the color wheel.
The contrast between triad colors is not as strong as that between complements.
Side note: If you are in a more conservative setting requiring a one colored suit, ties and handkerchiefs are a great way to get a few more colors into your color scheme while being appropriate.