Change the background color in VC Experience

Dear all,

When I learn the Lesson and watch the video_ “Record Camera Movements for Animations”, I found the document of .vcax type recorded in the video has the background color in grey. While the color of the background of my Visual Components Experience is always white.

Could anyone tell me how to change the color, and whether it is a new function is 4.2, because my version is still 4.0 right now.

Thanks and BR.