There are many styles of oil painting frames, you can match them according to your favorite style. Why don't you hang them at home and enjoy them?
Generally, solid wood oil painting frames can be used. Colors can be mahogany and rosewood. Mahogany color is commonly used, and it is most suitable for matching calligraphy characters. For example, the Ming Cuizhai Painting and Calligraphy Institute has frames of various colors. There is no hard and fast requirement, as long as you like it.