Why does gradual colour change appear more harmonious than sudden colour change?

Correct answer: It creates a smooth visual transition between colours

Gradation is a principle in which one colour changes progressively toward another through intermediate steps. Because the eye follows this continuous transition, neighbouring colours appear connected rather than abruptly separated, producing visual harmony. A sudden change creates a sharp boundary and stronger contrast, not necessarily harmony. It does not affect shape size or automatically remove texture. Hence option D is correct.