Color theory is the study of how colors interact and influence each other, as well as how they affect human perception and psychology. This can be used to choose colors that complement each other, create harmony, or contrast in your images. The color wheel is a circular diagram that shows the relationships between primary, secondary, and tertiary colors. The primary colors are red, blue, and yellow; the secondary colors are green, orange, and purple; and the tertiary colors are their combinations. Additionally, color temperature is a measure of how warm or cool a color is. Warm colors tend to convey energy, excitement, or passion while cool colors tend to convey calmness, tranquility, or sadness. Color harmony is a pleasing arrangement of colors that creates a sense of balance, order, or unity in an image. There are several ways to achieve this harmony such as analogous colors (next to each other on the color wheel), complementary colors (opposite to each other on the color wheel), triadic colors (evenly spaced on the color wheel), or monochromatic colors (variations of the same hue).