If a limited palette appears dull, how can variety be increased while preserving unity?

Correct answer: By varying tints, shades, muted mixtures, and textures

The governing concept is controlled variation within colour harmony. A limited palette can remain lively when the artist changes value, intensity, tint, shade, neutralisation, brush texture, and paint thickness while retaining the same base colours. Thus option B is correct. Adding unrelated hues may break unity, equal values reduce variety, and adding only black can muddy the mixture rather than create refined variation.