There is no definitive answer to this question as it depends on the artist's preference and intended effect. However, some colors are generally more popular than others for abstract art. Bright colors such as red, yellow, and orange are often used to create a bold and energetic look, while cool colors such as blues and greens can be used for a more calming or serene effect. As with any other type of art, experimentation is key in finding what works best for you.