How to take a solid color photo with a SLR camera

I don't know what the landlord means by solid color photos.

1, photos with only one color:

This is easy to handle. Buy a color card (available in many photographic equipment cities and art supplies stores), choose aperture priority mode, and set the shutter at F8, iso 100 when the light is sufficient, and shoot at will.

2, there are people, the background color is solid.

This is a professional job. You need a background wall of the desired color, as well as a light box, a background wall and a flash. General photo studios will have such equipment. If the equipment has any difficulties, it can be realized through PS, but if it is not done well, there will be distortion.