Artists use color theory to evoke emotions in their work by understanding the psychological effects of different colors on viewers. They may choose warm colors like red, orange, and yellow to convey energy, passion, or warmth, while cool colors like blue, green, and purple can evoke feelings of calmness, serenity, or sadness. Artists also consider color harmony, contrast, and intensity to create specific emotional responses in their audience. Additionally, artists may use color symbolism to further enhance the emotional impact of their artwork.