How to change chunk output background in revealjs presentation?

[LukaszDerylo]

Just like in title: I'd like to change code chunk output background.

I managed to change chunk clock background color with $code-block-bg variable in my custom .scss file but stucked with similar change to output background.

Currently my slides look like this:

[LukaszDerylo]

These few lines input in .scss do the thing:

div.cell-output pre code {
background-color: #123456;
}