The Jinhang Starship series refers to a line of spacecraft designs, and 'gradient color' typically refers to a color scheme that transitions smoothly from one color to another. This could imply that the spacecraft have a unique and visually striking color pattern. In terms of knowledge, gradient color designs are often used in aerospace to enhance the appearance of spacecraft and can also serve functional purposes such as camouflage or reflecting sunlight. However, specific details about the Jinhang Starship series and its gradient color design would require further information.