Add (white) margins on left and right to section with background color

[towu]

Hello, I would like to add a couple sections with different background color.

sec1
sec2
sec3

I would like to add a white space on the left and right of the inner section 2 (sec2). In HTML for this I add a left and right margin. Also in Elementor I can do the same but in the custom CSS section.. This can be a little cumbersome as I need to find out the ids first. I found a menu called "advanced control content" where I can set the margins. However the left and right is there greyed out and I can not set the left and right margin there.

Is there an easy way to do this?

Thanks for any help,
Tobias