Which term describes the depth and brightness of color in an arrangement?

The term that best describes the depth and brightness of color in an arrangement is intensity. Intensity refers to the purity and vibrancy of a color; it measures how bright or dull a color appears. High intensity colors are vivid and pure, while low intensity colors appear more muted or grayed.

In the context of floral arrangements, understanding intensity helps in creating visual impact and harmony, allowing the arranger to achieve the desired emotional effect. For example, a bright, intense red flower can create a striking focal point, while softer, less intense shades may be used to create balance or subtlety in the design.

Other terms such as shade, value, and tone do refer to color characteristics but in different ways. Shade typically indicates a color that has been darkened by adding black, value refers to the lightness or darkness of a color, and tone involves the alteration of a color by adding gray. While these concepts are important in color theory, intensity is specifically the measure of brightness and vibrancy, making it the correct choice for this question.