Sarcomyxa edulis, a notable edible and medicinal mushroom indigenous to northeast China, is celebrated for its high nutritional value and delightful taste. In this study, white light as a control and examined the effects of red, green, and blue light on the agronomic traits, antioxidant capabilities, and nutritional composition of S. edulis. The results showed that different monochromatic light qualities affected the color of S. edulis pileus, with blue light demonstrating particular efficacy. Furthermore, blue light also regulated pileus length, whereas red light was instrumental in significantly increasing stalk length. Regarding antioxidant capacity, compared with red and green light, the activities of POD, SOD, and CAT were significantly improved by blue light irradiation, decreased MDA levels, and improved free radical scavenging potential. Additionally, blue light exposure led to an increase in the contents of 15 amino acids. Green light treatment reduced the crude fat content. For the first time, we found that light quality is a key factor in controlling the color of S. edulis. Blue light is an effective way to regulate the color and pileus size of S. edulis, and improve the antioxidant properties. The photobiological characteristics and the response of nutritional quality to light environment of S. edulis were clarified.