The color of the photo taken on a white background is gray, and the background is not white.

1, if the color is wrong (such as magenta, etc. ), is the problem of white balance (some entry-level SLR, such as 500d). Ambient light and the color temperature of the lamp will affect the background color. (The gray card can calibrate the white balance. )

2, the color is colorless (no color) the background is gray, that is, the light problem, whether the light shines on the background, whether the background is too far from the main body, and so on.

3. It is also possible that the exposure is insufficient or the subject reflects light, and the white background is white, resulting in gray background, so you can increase the exposure when shooting. Or the ps curve brightens.