Why can lack of color also be expression in art?

Because limited color can create an atmosphere of mourning, seriousness, or memory

The governing concept is that artistic meaning can be created through both presence and absence of visual elements. A monochrome, grayscale, or deliberately restricted palette can reduce visual excitement and suggest mourning, seriousness, silence, memory, distance, or emotional restraint. The viewer interprets the chosen limitation in relation to the subject and composition. Thus option A is correct: limited colour can establish a particular atmosphere and express an idea without bright hues. Option B is false because drawings and paintings can use many approaches to colour, including none. Option C wrongly assumes laziness, although restriction may be a thoughtful decision. Option D is also false because many colours, contrasts, and even neutral tones can communicate emotion.

This is a Class 9 Art Education question. Chapter: Introduction to Art. Topic: Art as a form of expression.