Which design is based on equal proportions of color and shape?

The correct choice regarding a design based on equal proportions of color and shape is the symmetrical design. This design type maintains balance and harmony by ensuring that both sides of the arrangement mirror each other in visual weight, color distribution, and shape.

Symmetrical designs are often characterized by their formal and organized appearance, which is achieved by using equal proportions of color and shape on either side of a central axis. This balance is visually pleasing to the eye and creates a sense of order and stability.

In contrast, intermediate colors refer to the hues created by mixing primary and secondary colors but do not specifically relate to design principles. Asymmetrical design involves an intentional imbalance to create a dynamic look, focusing more on the visual weight rather than equal proportions. Round design typically emphasizes a three-dimensional form that radiates outward, but it may not strictly adhere to equal proportions of color and shape. Thus, symmetrical design is the best answer for the question posed.