may I ask how to define the background color as rendered?

The default one seems to be black and I'd like to set it as a white background or in other color.

Thanks!

I'm not sure is the right way but you can create an environment light and in

Light Tab > Render Options > Ray Tracing Background.

And Check > Render Light Geometry

Hi Oat,

Two more options:
1) give up adding background color in 3D, and use compositing nodes on your render output to add a background color - e.g. using “color” node (you must override the defualt resolution in the node)
2) make a grid, attach (parent) it to your camera and push it forward, beyond your furthest objects in the scene. Then add a constant material with a chosen color.

Cheers,
Greg