How to set black and white wallpaper for Apple mobile phone?

1. Take Apple 8 as an example. First open the settings, as shown in the figure below:

2. Then click General, as shown in the figure below:

3, and then click the auxiliary function, as shown in the figure below:

4, and then open the display adjustment, as shown in the figure below:

5, click on the color filter, as shown in the figure below:

6. Slide the color filter button to the left to open it, as shown in the figure below:

7. In this way, the mobile phone will change from black and white to color, as shown in the following figure: