As a vital component of the painting art, oil painting landscape sketching showcases the beauty of nature and the emotional world of the creator with its unique charm. In oil painting landscape sketching, color stands as a crucial element. It not only objectively represents natural scenery but also directly expresses the creator's subjective emotions and aesthetic concepts. The subjective expression of color endows each oil painting landscape sketching work with unique characteristics, imbued with the creator's personal touch, and serves as a bridge for emotional communication between the creator and the audience. A thorough exploration of the subjective expression of color in oil painting landscape sketching holds significant importance for understanding the essence of artistic creation, enhancing the artistic value of works, and promoting the development of oil painting art.