Step 1: Differentiate between the elements of art and the principles of design. The elements are the basic building blocks of art (the what), while the principles are how those building blocks are organized (the how).
Step 2: Classify the given options.
The elements of art are typically listed as: Line, Shape, Form, Space, Texture, Value, and Colour.
The principles of design are typically listed as: Balance, Contrast, Emphasis, Movement, Pattern, Rhythm, Unity, and Proportion.
Step 3: Identify the outlier. Colour is a fundamental {element} of art, not a {principle} of design. The principles (Contrast, Balance, Proportion) describe how colour and other elements are used.