A single hue and the tints and shades of that hue. Tints – add white, Shades – add black.
Colors that are adjacent to each other on the color wheel. For example: red, yellow, orange, and blue, green, violet.
Colors that are directly opposite each other on the color wheel. For example: blue-orange, red-green, and yellow-violet. It is always a warm color and a cool color.