How to adjust the white balance in digital photography to accurately restore colors?

This only means that the book you bought is wrong ... I'll type it slowly later. ...

In fact, you'd better find the white balance in digital photography at that time and store it in raw format, and adjust it in the curve when you go home to PS, which is more convenient and accurate than on-site search.

The most accurate way to find the correct white balance when shooting is to bring a color comparison card, which is generally pure white, pure black, medium gray, and may also be accompanied by a light gray. Put the color chart on the object you want to shoot, and the camera is facing the medium gray scale. In addition, white balance can also be found for objects close to medium gray level.

Also, don't completely abandon the camera's preset white balance, which is sometimes very easy to use.