Colour Wheel and Colour Relationships

Complementary colours sit opposite each other on the colour wheel and naturally create strong contrast. That contrast becomes controlled when dominance, area, and saturation are managed—for example, a muted large field can support a small, vivid complementary accent. Equal full saturation or uncontrolled harshness competes everywhere, while an unrelated clash lacks harmony. Therefore B is correct.

The governing concept is complementary colour interaction. Complementary colours lie opposite each other on the colour wheel, so transparent overlapping layers can absorb or counteract parts of each other’s light, reducing saturation and producing a dull, neutral-looking mixture. Therefore D is correct. A predicts increased brightness, while paper choice and brush size do not normally explain this systematic loss of chromatic intensity.

Value describes relative lightness and darkness, but it is only one part of colour organisation. Option A is correct because colour temperature, saturation, and complementary relationships can still conflict even when the values match. For example, an overly saturated warm area beside a cool, muted area may look disconnected. Paper size, using one suitable brush, and neat outlines do not by themselves determine colour harmony. A complete review considers value and relationships together.