What are cool colours? What effects do they have in design arrangements?

Cool colors are typically shades of blue, green, and purple that are associated with calmness, tranquility, and relaxation. These colors are often used in design arrangements to create a sense of serenity and peacefulness. Cool colors can also make a space feel larger and more open, as they tend to recede visually. Additionally, cool colors are often used in combination with warm colors to create a balanced and harmonious color palette in design arrangements.