Dian lian niu zi

Quick answer：

Dian lian niu zi is a traditional Chinese painting technique that involves blending colors in a soft and subtle manner, often used to depict the purple flowers of the morning glory (Ipomoea nil) in a delicate and elegant style. It is a part of the broader category of Chinese ink painting, which emphasizes the use of ink and wash techniques to convey the essence of the subject rather than detailed realism.