Which principle involves a pleasing arrangement of different colors in a composition?

The principle that involves a pleasing arrangement of different colors in a composition is harmony. Harmony in design refers to the cohesive blend of colors, shapes, and textures that create a sense of unity and visual balance in a floral arrangement. When colors harmonize, they resonate with each other, enhancing the overall aesthetic appeal and ensuring that the composition feels complete and well-integrated.

Harmony can be achieved through the use of analogous colors, which are next to each other on the color wheel, or by using complementary colors in moderation to create interest without overwhelming the viewer. This principle is essential in floral design, as it helps to evoke emotions and conveys a specific theme or mood.

The other concepts, while important in their own right, do not specifically focus on the arrangement of colors. Contrast emphasizes differences between colors or elements to create visual interest. Balance refers to the distribution of visual weight in a composition, ensuring that no one part feels heavier than another. Rhythm pertains to the movement within a composition, achieved through repetition and pattern, guiding the viewer's eye throughout the arrangement. While these principles are valuable for achieving a well-rounded design, harmony distinctly addresses the pleasing arrangement of colors.