Why should enough space be kept between colours on a palette for clean blending?

Correct answer: To prevent unwanted colour mixing

The governing concept is organised palette management. Separating paint portions prevents neighbouring colours from accidentally touching, spreading, or becoming muddy before the artist intentionally mixes them. The clean space also provides room to combine measured amounts and create a controlled blend. Thus option B is correct. Spacing colours does not make the palette heavier, speed drying, or change the size of a brush. It protects colour purity and supports deliberate mixing.