Flat composition refers to a design technique that involves arranging elements on a two-dimensional plane to create a balanced and harmonious composition. Warm and cold colors are used in visual arts to evoke specific emotions or convey a particular mood. Warm colors, such as red, orange, and yellow, tend to advance and are associated with energy, passion, and warmth. Cold colors, like blue, green, and purple, recede and are associated with calmness, stability, and serenity. In the context of flat composition, these colors can be used to create a sense of depth, guide the viewer's eye, or emphasize certain elements within the design.