Yes, you can use a lighter paint color over a darker color to achieve a faux effect. This technique, known as layering or color washing, allows the undertones of the darker color to subtly show through the lighter top coat, creating depth and dimension in the finish. It is important to note that the success of this technique depends on the type of paint, the preparation of the surface, and the quality of the application. For best results, use semi-transparent or glaze-like paints for the top coat, and ensure that the underlying darker color is fully dry before applying the lighter color. Additionally, consider experimenting with different application methods such as sponging, ragging, or stippling to enhance the faux effect and add texture to the finish. Remember to test the technique on a small sample area before applying it to the entire surface to ensure the desired result is achieved. By carefully selecting your paints, preparing the surface properly, and implementing various application techniques, you can successfully create a beautiful faux finish by layering a lighter paint color over a darker color.