What is the reason for the uneven color in indoor flash photography? All black products have patches of color. You can look at the picture and see if it looks dirty.

This may be a quality problem with the notebook itself. It is not obvious to the naked eye, but it will be obvious when photographed with a high-definition SLR and flash. Another possibility is that the notebook itself is dirty. If there is any contamination, you need to wear gloves to clean it carefully before taking the film, and observe the correctness before taking the picture.